If you don't already have your heart set on a specific tattoo design, the tattoo parlor you choose should be a good source of inspiration. Most tattoo artists have at least one wall where you can view their designs, and have a lot of fun while you're doing it.
Always have a clear head when you walk into any tattoo parlor. While getting a tattoo is usually something you do after loosening your inhibitions a bit, recklessness may cause you to end up with something that you don't really like -- and tattoos are permanent.