kurtaztrophe:

Its a mix and match game! Even in the show, as an example some character’s have the same type of face shape, but have a different type of nose shape. You can even come up with your own or mix 2 different things together!

So mix and match or mix them together!

Gem type, placement of gem, and personality is all up to you.
Clothing can be whatever you want, I would try basing it off of personality or gem type job, but if you are trying to go closer to canon (like homeworld gems), look at different canon homeworld outfits, and go from there.