I can probably help you draw floor tiles. So when you say "thin boards", do you mean like hardwood?
And, for good critique on your art, venture on over to the Pixelation forums
. A ton of talented artists go there, and a lot have industry experience. There's also plenty of new people who're there to learn and improve.
They'll pick apart the problems with your art and help you realize things you probably wouldn't see otherwise! There is also a lot to be gained by viewing other peoples' art, and studying how they do things.
There are a wealth of threads on various things like color selection, anti-aliasing, selout, dithering, the restrictions from various consoles. They even have critique of a bunch of popular commercial games' pixel art! It's pretty handy stuff.