Nail Design Tips

Here are some ideas to get you a perfect nail designs from the professional hail designer.
Don't use crazy glue to glue decorations to your nails, even over layers of polish! It will eat through polish and can ruin nails. People have suggested nail glue but I have had problems with that too I tend to use clear polish as glue and then apply a clear coat or two over the decoration and nail to lock it in.

Experiment with layers of colors. Many reds look regal over a coat of gold. Silvers and metallic grays look great over black. Many opaque shades or shades with pearl-like attributes look cool over black. As usual, make sure each coat is dry before applying the next. I have never actually mixed colors together before application since it seems too messy to bother.
Add depth to some shades, especially metallic colors, by alternating coats with clear polish.
Wear cool rings! Why? Because your nails will attract attention to your hands so dress them up a bit!

For creating nail patters:
cut a "band-aid" into patterns and stick it on top of a dry coat of color polish. Apply another color over the previous coat and the band-aid and let dry. You'll have to be careful as it is easy to turn up the edge of the band-aid and ruin the pattern. When you peel off the band-aid you'll have a design the color of the lower coat. The reason I use band-aids is because the glue isn't meant to be harsh as it goes on skin and can be peeled off easily. The other neat thing about them is they often have small holes that the polish can seep through and leave small dots as a pattern.

Nail piercing creates a very interesting affect, but can also weaken the nail. If only for the piercing tool since it is less likely to cause a split than a pin or razor blade tip, and is more manageable. Always apply a few coats of polish before making the hole and don't make the hole too close to the sides or the tip to help avoid splits. I have not tried this (yet) myself, but Syryanni, who has experimented with this, suggests placing the piercings on nails where they won't get caught such as the pinky vs. the index finger. It was also suggested that the piercing could be done on the upper portion of a long nail so that the hole could be filed away without loosing too much length. (Salons can also make the piercings if you are not comfortable doing it yourself)
Using a toothpick and different nail colors you can make designs on your nails, such as little bats or a cast iron swirl. There are also special brushes designed for nail art but the toothpick is stiffer, making for better control. There's also on the market a "design" brush consisting of a polish bottle with a long thin brush for doing lines and streaks across nails.
As with the above, experiment with Chinese characters. (Such as red characters on a black base.) Theban Script (a.k.a. the "Witches' Alphabet") and alchemical symbols would also make for an intriguing look.
If you have long nails, try painting the underside of the nail (the part you see when looking at your palm) with a contrasting color. Choose a dominant tone for the topcoat, and an accent tone for the underside of the nail. For example, black nails with silver on the underside would make for a great effect on the dance floor for Goths who (like me) like to use their hands a lot. The trick is to keep it subtle - the color on the underside of the nail, that is, not your dancing! When polishing the underside of the nail, avoid getting polish on the hyponichium, the area where the skin and nail meet.
Once I painted my nail silver and placed squares of silver glitter on one by one, sticking them with clear polish. My nail looked like a disco ball. Afterwards I sealed in the pattern with a couple of layers of clear polish and that preserved it nicely. I do synchronized swimming but the design didn't come off in the pool.
If you want to do the whole nails as weapons motif what I find works well is if you take a small hole puncher and use it on the edge of your nails to get a scalloped effect on the edge of the tip of the nail. Then looking sideways at your nail, file it at an angle so it creates a blade's edge effect. So in the end you end up with the equivalent of a serrated knife for a fingernail.
Brushing a metallic eye shadow over slightly wet polish and covering it with a clear coat after it is dry makes for an interesting effect. I tend to use silver over black nail polish but other color combinations work well too.
I've had some luck using paint pens over a coat of colored nail polish to draw designs on my nails and then going over it with clear stuff to make it stay.
Reading your site I came across the part about nail piercings. A good way to prevent the nail from breaking where you put the hole is to place a small blob of acrylic where the hole is to hold the piercing in place this is especially good if its a dangling decoration as it stops the little loop thingy moving about too much and it less likely to get lost.
To get super precise patterns on your nails, try using gel pens, eyeliner pencils, or even normal pencils to (gently!) draw the pattern on. Then seal it with clear polish. The only major problem with this is that most pencils won't stick to nail polish so it needs to be applied right to the nail, but I haven't had any problems with it staining the nail so it should be OK. My favorite pattern is a simple diagonal line across the nail, with one side filled in with a normal pencil and the other side filled in with a light silver gel pen; I've gotten a ton of compliments about it.
I have found that if you paint you nails black, (or any other color) and then use nail polish remover to remove a bit of black in the center, leaving black near the cuticle, and at the tip, then painting over another color makes an interesting look.
If you paint a solid coat of a dark blue on your nails first, then paint a thin coat of a transparent black on top it gives it a pretty cool effect of black when there is no reflection of light on your nails, but when there is light reflecting off of them, you can see a tint of dark blue/navy coming thru. I use the NYC and Elvira brands of nail polish and am pretty successful using them. Elvira nail color is best for transparent colors. NYC is best for solid colors and base/topcoats.
This is one of my favorite things to do with my nail polish: Apply a thick coat of a lighter color, such as red or silver, and let it sit for a minute or so, then paint black over it. After the black polish is fully dry, use a q-tip to rub nail polish remover onto your fingernails until you start to see the first color. It's a nice effect if you do it well.
I've found a really great way of doing nail design is by using one of those "gel ink" type pens. The upside with these is that you can draw on your nails, and if you don't like it a wet tissue will wipe it right off. Once you get it right (which can take a few tries) let it dry and seal it on. It can make some really dazzling effects. Letters are easy, even cursive letters. Runes, scripts, or my personal favorite's crosses and spider webs. It works a little better if you're ambidextrous. If you're good, you can do anything. Darker colors tend to be "watery" a little translucent. Brighter colors will tend to be good and thick, perfect for going over black. Gold runs over red is breathtaking. I once did some little smiley faces for a friend. I cannot recommend these enough. They don't do any damage to nails as long as they're OVER a some kind of polish coat (most are made for scrapbooks, and so have to be mild for archival reasons). And ALWAYS coat over them or they'll rub right off. Coat generously (two or three) and re-apply every few days. The designs can last a month or so, as long as the polish doesn't start to chip up too much.
If you want to put dark red in the center with black on either side, it will be easier if you first paint the entire nail black (let it dry thoroughly), then use white acrylic paint (the kind sold in craft stores) over that in a strip down the center, making the white strip as wide as you'd like the red to be. Acrylic paint dries fast, and after it's dry, put the dark red polish over the white stripe. The white underneath will make the red polish stand out very well, as opposed to just painting red over black, which is unlikely to show up at all. When your nails are completely dry, put at least two coats of clear polish/hardener/top coat over them and reapply the top coat every other day to make the polish last.

The marble effect:
Get a container (that you don't really want to keep) and put about an inch or two of water in it. Get two or three colors of nail polish that you like and add a few drops of each into the water. Take a tooth-pick and swirl the nail polish around. Dip each nail into the nail polish and water. *Make sure you dip your nail into a transparent-type swirl. If you dipped it into the solid looking stuff, all you would get on your nail is a big round glob of nail polish. Wait for the nail polish to dry. (It shouldn't take that long because it is a fairly thin coat.) Take nail polish remover and put some on a cotton pad. Take the nail polish off of your fingers except for around the nail: you can do that with a q-tip later. After you get the messy nail polish off of your fingers, now you can get the q-tip and carefully remove the nail polish from around your nails. Carefully wash your hands to get rid of the smell of the remover. Go out and show the world your fun nails!

Crazy designs:
Instead of using band-aids for the patterns, painter's tape works just as well, and you can cut out little designs, or mask away parts of the nail that you don't want covered up. I normally put a coat or two of silver or dark, blood red as the bottom coat. Then I wait for that to dry. Next I cut out thin, long spikes (triangles), and place five on each nail. One going down the centre of the nail (but not touching the cuticle area. You might want to keep the tape about 3 or 4 millimeters away). Then I put one on each side of the nail in the centre (it now looks like a cross sort of). Then I put the others in between the side and centre tape. *Keep in mind that none of the tape touches each other. After the tape is on and positioned right, I then take black nail polish and put a coat or two of that on. When that dries I remove the tape, and put a coat of clear nail polish on.
Snake skin nails:
 
Paint your nails with one coat of beige. Dab in a few chocolate-colored diamonds down the center of the nail (don't make the diamonds perfect). Apply one coat of copper/bronze nail polish over the entire nail. Wrap a piece of tulle around each nail while it is still tacky, and have some of the polish squeeze through the fabric's hole. Peel the tulle away from the nail from the tip to cuticle.

The Burberry effect:
 
Apply a base coat of beige. Dip a one-inch stripling brush into a black polish and lay the hairs on the nail and pull straight down for the vertical stripes (total of 3) and straight across for the horizontal stripes (total of 3). Repeat the second step with a burned brown color (or you could use the copper, bronze or chocolate colors) to make 3 horizontal and 1 vertical stripe on the nail. Apply a stripe of beige on top of each horizontal brown stripe to mute the color. Highlight in between the black stripes with white nail polish. The one-inch stripling brush can be found at any beauty-supply store.
Contrasting colors on just one nail look great, I like to do my nails black with pink or red on the index finger, but any color looks great. French Manicures look good too, black with pink tips and pink with a black tip is one of my favorite designs, just make sure you put a coat of clear varnish on the top to protect the tip colors.
Fake tattoos work really well for designs on the finger nails. All you have to do is paint your nails like normal and then cut the design you want from the fake tattoo and then do the same as you would for putting it on your skin. To make it last long just put a couple clear coats on top