Hi there, Here are my two cents:
do not use a cloud modifier, without modifying it.
I would first start with a base color, say yellow in this case
then i would use a cloud modifyer on a ind layer and lowering the opacity
then on the third layer a noise modifyer, also on low opacity.
then i would paint out scratches using a burn or dodge tool.
these are all available in PS CS3, howeve ri noticed you were using paint.net
if thats any good then it should have all those tools available.
Keep on it and you will get better, look up a few tutorials online =)
[Q]uik, Quiker than most