I've had lots of fun doing the occasional challenges. I've even put out requests for some to do in the future, and I'll get around to them, I swear!
Upcoming will be Labyrinth nails (from the movie), Harry Potter (in time for the last movie release!), and Nintendo nails - Mario, Zelda, or MegaMan. I have a feeling I'm going to have an absolute blast with them.
Pretty soon, I intend to get a set of plastic false nails attached to sticks which will allow me to paint on scenes and then display them for anyone I'm doing nails for to browse then pick out what design they'd like applied. I figure this will solve two purposes - let me do a semi-ornate design NOT on my own finger (this simplifies things!), and give me a template to follow for a guideline. Because when I'm freehanding a design, it tends to fall almost invariably into one of two designs - flowers, or flying insects. Generally insects with flowers.