I made an alien race based on Tolkien's Elves. Now if only I could figure out how to take a darn screenshot. Curse my lack of tech knowledge and patience!
If it's a playable character, you can PrtScn in the Character Creation screen. For playable characters and BOffs, visit the tailor at the Space Dock, edit the uniform, then PrtScn, then just Back/Back/Back out of it. The tailor charges no fee for this fine service. Probably because he's a Cardassian, not a Ferengi, but I digress.
You'll then find those screenshots inside your STO folder, saved as JPG files.