You can cut the end off of a toothpick, then dip it in nail polish (a different color than the base color obviously haha) and make two dots and then a smaller one in the middle. this makes a really cute bow!

Or you can do your tips in glitter polish.

Or use a sponge to do a gradient nail. (this one's hard to explain but you could probably look it up and find out what I mean. )

i don't know exactly what you're into but for me I LOVE NAIL ART i'm an obcessed decora fan so i have fairly reasonably long nails and i glue glitter, nails art stickers, toki doki decorations and all sorts of things on them :) i love it but you need a really thick nail polish. another cute on is cupcakes ( see pictures) or jsut plain and simple do your nails in bright pastels, ( contradiction?) and do a polka dot of different colors....... another one if you have time is water marbling i can't really explain how to do it but it's easy to find on google :)
note: the one with the exclamation marks is a fake nail in this picture, but if you have a steady handed artistic friend, i bet they could do it! i've done it before but i can write with both my hands :p
hope it helps!

Try color blocking your nails! It's sooo easy! Or you could do the "crackle" nail effect, but the nail polish is like 7 dollars, which I think is outrageous but whatevs! for color blocking just pick your fav colors and paint stripes or triangles or whatever! Every nail can be different so its hard to mess up! and for the crackle you just coat a nail with regular polish, then apply a coat of the crackle polish, it will just start separating over your nail :)

I think some skin care online sites offer tutorial or DIY nail designs,you can visit them if you wish too.

http://girlstalk.ca/

Not sure if this is what your after but have you seen the magnetic nail polish range that's out? You paint your nails and then hold the magnet that comes with it over your nails and it forms patterns :) http://www.magneticnailpolish.com.au/