I am not a good spriter myself, but I looked at so much sprites (yes, MUCH) to know what spriting is.
DO NOT SAVE AS .JPEG/.JPG. It totally rapes the quality, and I've been reading so much about it so many times on the forums.
What the... You just copied and flipped the thing and then stuck the thing together! Do you even know what spriting is?
The trainer cards... No, just no. That's not spriting. You just made some place into a background and slapped some sprites THAT WERE NOT MADE BY YOU on it.
What the heck is this?! OK, you actually did sprite and recoloured the Poke Ball, but you just copy-pasted the body parts of a Pokemon onto it! NO!!! Spriting is not just like that! Spriting requires you to do some scratching, and so on... And you saved as .jpeg again!
And what's with adding Pokemon parts to a Pokeball anyway? Yes, it is art, but it makes the Pokeball really strange and such. But some people still would repaint their ball, like Kenji just said... And does anyone ever think that it heavies the Pokeball's weight? Mou...
No, just no... This isn't spriting at all! Don't you read the rules or something?! And wait, don't go just yet! You saved this as .jpeg, didn't you?! Someone told you not to already!
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So far, I am not exactly happy with what you made. Perhaps you should do recolouring or revamps/devamps? It would suit your style well, seeing how you pulled your skill off in recolouring. Try that, it's fun. If you practise more, you'd make a really good spriter.