If you are like me, and like to use lightweight window managers, you will probably face a problem if you want to enable even the basic visual effects since you cannot run two window managers at the same time (example: Fluxbox conflicts with Compiz). These problems can be however solved quite easily with a program called xcompmgr which is usually found inside Linux package repositories. Once you install xcompmgr you will have the ability to get some basic effects to your Fluxbox or more demanding effects to your Openbox setup. If you need additional info about xcompgr check manual pages (type man xcompmgr inside a terminal client).
1. Below is a screenshot of Fluxbox running with xcompmgr -c & entry inside the .fluxbox/startup file.
Note: Personally I have found that there are some severe performance impacts if you wish to enable xcompmgr inside Fluxbox with more than just the very basic eye candy.
2. With Openbox things are however a bit different as it works very well with xcompmgr, even with a lot more demanding settings, without virtually no performance impact at all.
Below is a screenshot of Openbox running avant-window-navigator(themed) with xcompmgr -fF -I-.004 -O-.004 -D2 -cC -t-4 -l-6 -r6 & entry inside the .config/openbox/autostart file.
Note: The big dark bar seen at the bottom of the screenshot is a result of a screenshot program bug not an actual state of Openbox running xcompmgr. Xcompmgr works just fine inside Openbox.