Since there's literally thousand of different geckos, which makes it near impossible to just memorize all of the various latin names, what I try to do is whenever I come across a gecko that I see that I like, I look it up on google and memorize it's latin name. That way, I can put the visual of the animal AND it's name together in my head. The more than you do this, the more it simply becomes habit, and before you know it, you'll have tons of them indexed in your brain!