sometimes when you are customizing the UI of a flex component you just want to make small changes and you don’t need a lot of help, but sometimes you need to tweak it completely, so adobe, like many things, create a lot of tools and, mortal people like me doesn’t know about those…
but a friend tell me one !!!, the style style explorer, check it out
http://examples.adobe.com/flex3/consulting/styleexplorer/Flex3StyleExplorer.html#