I did this guide about the different types of tattoos. if you think I forgot something, please let me know!

Categories
Lettering: http://1337tattoos.tumblr.com/tagged/quote
Black&White: http://1337tattoos.com/tagged/bw
Tribal: http://1337tattoos.com/tagged/tribal
Biomechanical: http://1337tattoos.com/tagged/mecha
Japanese/Asian: http://1337tattoos.com/tagged/japanese
Dotwork/Geometric: http://1337tattoos.com/tagged/dots
Watercolor: http://1337tattoos.com/tagged/splatter
Blackwork: http://1337tattoos.com/tagged/blackw
UV tattoos: http://1337tattoos.com/tagged/uv
White ink: http://1337tattoos.com/tagged/white

*nope, I don’t have a category for new and old school because at least 60% of my daily posts are in these styles. you can look for something more specific on the categories page.

Sources 
http://magazine.foxnews.com/style-beauty/tattoo-style-guide-part-1 
http://magazine.foxnews.com/style-beauty/guide-tattoo-styles-part-2
http://www.tattoo.com/blog/sacred-geometry-tattoo-decoding-trend
http://beauty.lovelyish.com/2013/06/09/hot-or-not-watercolor-tattoos/
http://tat2guru.com/dotwork-tattoos-creating-art-with-millions-of-tiny-dots/
http://en.wikipedia.org/wiki/UV_tattoos
http://www.wisegeek.org/what-is-a-white-ink-tattoo.htm
http://blog.smashcave.com/collections/hyper-realistic-tattoos-you-wont-believe/