If you have interest, you should check out the base assets provided for modification during the Liberated Pixel Cup that was held in 2012 by OpenGameArt.org. The contest was done to help create open source art assets for game developers to make demos with - all entries can be used for free, even in commercial projects, so long as attribution is given (but you'll have to view the text files and licensing info for official details). Here are the
base assets from the competition to check out (there's also a page where you can
view them without downloading them, if you want to view them out first). And here are just the
terrain tiles in case you only want those. The rest of the site also has general game assets that are free to use (under varying licenses) and entries from the contest based on the assets provided above can be found, too. ^^
Just thought it might be useful for future endeavors! These tiles are all around larger than Pokemon-style ones, however. If you ever find yourself working with tilesheets, rather than working by hand, I recommend a free program called
Tiled to make things easier.
It is, of course, most awesome that you've made your art yourself! But perhaps these resources could still be helpful/inspirational.