brushing isnt hard at all...you just need to try it...here ill tell you how to brush something, i know its the basics...but heh it works >.>
1)Start a layer, use the cloud filter (for better effects)
2)Create a new layer, take 1 brush, tap a few times at different places, set blending mode to soft light (use foreground color black)
3) do this about 4-5 times with different brushes each time
4) take a new brush set your foreground color to white, brush a few times, set blending mode to softlight
5) use color balance (adjustments menu) to pick a color
6) new layer, ctrl+a, edit>stroke> 1 px border
7) add any other crap and you have yourself a sig =D
this is one basic style of brushing, using different brushes, styles/blending modes and SOMETIMES a filter (filters mostly suck, but you need to use the cloud filter in this style or else you get a really weird half transparant background....unless you use a basic black or white background...but thats crap >.<)