Be not afraid of HTML....
To make something on your blog opaque. This can apply wherever you want. Just make sure it comes under the right "header".
For really nice backgrounds, plus follow her quicky-instructions on right side to add background anywhere on blog page, from any online source. Means you can make your own backgrounds, if you want to.
Will add more as I go. When I find time, will add seperate posts for specific tips that I found helpful. Like adding 'tables' to any blog. There were two steps that I don't want to lose. Er. I just have to find them. :)