First off, to let you know, you can find Castle icons from every episode (season 2) at my
livejournal. I usually do them by the week, but sometimes I get busy or lazy and wait longer. It's easier to find them there than to post them here, since I make so many.
Here's some other Castle art that I have made, that cannot be found above.
This is a colorization, I first turned the photo black and white and then colored it in Photoshop, for those who aren't sure what that is.
If you would like any of the icons below, let me know and I will crop them for you.
Some signatures.
A very small banner, height wise.
More signatures, older, haha.
That's all I have to show off at the moment. You're welcome to use any of it, so long as you credit me.
Enjoy!
Jessica's Art
I've stolen the bottom one, but the Stana one right before it is my next fave for sure. 
