The most common mistake that I’ve seen is not taking full advantage of mxml. New Flex developers tend to reinvent the wheel a lot by programming something that Flex already has a built-in solution for. For example, they are unaware of how to use states and transitions, or they are unaware of all the things you can do with data binding. So they write a lot of ActionScript with tightly coupled views instead of writing small amounts of Actionscript and using mxml for all that it can model.

Nice articles, Jon! Would you be interested in speaking on this topic at an upcoming meeting of the (Denver-based) Rocky Mountain Adobe Users group? I think discussing misconceptions, mistakes, and fallacies in Flex development would be of interest to our group.

If you’re interested, please let me know and I’ll give you more details.