I think that the most important part of spriting Pokemon is making the line art look right before worrying about anything else. Eveelution, your sprite has too many straight lines in it... Organic things are usually rounded. You should try to make the paws more circular, and avoid right angles.
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If you want your sprite to look like a Pokemon, you should give it a large head, with recognizable facial features. Check out these sprites, made by Galatea. They have all the hallmarks of a well-designed Pokemon sprite: clean line art, Pokemon-ish faces, nice colors, good shading, an angle which makes it seem as if they're facing an opponent, and just overall good designs.