Uh... just saying, "looks nice" doesn't really help in my opinion.
I'm going to say that you avatar and banner is not very good. The reason for this is because I can't read what it says. The banner cuts off on the side for both the words going across the entire banner and the "---cing" on the left side. Unless that is what you were going for, you might consider fixing it so that all the wording fits and viewers can read it. I'd also suggest putting a border or a shadow on the words that go across because the color scheme makes it fade into the background and makes it--again--hard to read; another option is to increase the space between the characters or put the layer with the words above the layer with the paint drips. Basically, if you make things more legible on your banner, it would look much better.
What file type did you save it as? Quality-wise, it's "okay" and that's because it's grainy. If you saved it as a JPEG, I'd suggest you change it to a PNG file instead to increase the quality. One more thing about the banner is that the "DA" is off-centered which bothers me quite a bit. You should probably fix that since the rest of your banner looks good in terms of design.
You avatar is okay. The thing that I'd suggest is to make the words on the top pop out more somehow. Perhaps a stroke, a shadow, changing the color, or bringing the layer above the diamond shape. I honestly have no idea what that is meant to say because I can't read it. I like the color scheme. The yellow really brings out a presence to the avatar.
As for your thumbnails, I think they are very well made. You can tell what it is about and everything is legible on the thumbnail. I think they are simplistic but very nice and they pop out when I go to your page.
but I think the banner is best! 
