So yeah, these were recommended to me by a friend. They're a lot of hard work but the end product is pretty cool. Basically you take origianl artwork, outline it, remove the original and colour the outline in the colours from the game sprties. I'm still only just starting at this so my first attempts are a tad phail.

Oddish:

Cubone:

Im liking the Cubone one. I might have a go at a Sableye one.

Yeah i recommend it greatly. I'd also say start with a complex one, something with an outline that's not a basic object (Sableye would be cool)