I'd try to get away from using brushing as your main source of a background. Start reading tutorials so you can learn the basic elements (flow, depth, composition, lighting)
I agree. I used to brush my BGs as well. Then I'd slap on a render and... TADA! Sig!... not.. lol Just wait untill you get to the good stuff. ^_^ It's sweetness. Tuts mate, tuts.