NOTE: Below is part of an answer to a private communication. I post it here because it can be interesting fot other users:
Most of the time I try using the styles already defined by Wolfram Research, it is just faster. In the workintegral example that you mentioned I used the style that can be obtained by opening a new notebook and then select from Mathematica's 7.0 menu: "Format-Stylesheet-Creative-Natural Color".
Another style I like very much is the style "Format-Stylesheet-Report-Standard Report". The feature I like most about those two styles is that it is very clear what output corresponds to what input, because they end up "framed" together.
When defining banners for your own styles, for the banners you might try working with "docked cells" (http://reference.wolfram.com/mathematic ... Cells.html)
You might find useful the following links:
http://forums.wolfram.com/mathgroup/arc ... 00447.html
http://forums.wolfram.com/mathgroup/arc ... 00168.html
I hope that helps