RE: King Arceus' Artwork Newest Addition (Kyurem, Delibird, Charizard 03/02/2012)
As a spriter, I should tell you that you should always enlarge sprites in intervals of 100, not 50. It prevents some of the pixels in the sprite from becoming rectangular when enlarged.
Hope you take my advice!
I can see a steady improvement through your updates, but don't be afraid to step out of your comfort zone. In art, skills are often transferable, and you'll find that practising something new will help you greatly in the things you have done before.
As you often include landscapes in your art, I think you'd find it beneficial to try and digitally paint some real life landscapes. Nothing fancy, and don't ever be afraid to produce a "bad" drawing. It's the practise that counts, and it will help tune your senses of perspective and colour. This picture would be a good exercise to start with. : )
I'd also recommend The Fire Wyrm's advice, be careful of how you scale those sprites. Good luck and persevere. : )