As a rule, I don't use direct on-camera flash for macro photography...for obvious reasons which we all understand. When I photograph models, I usually have some full spectrum fluorescents and reflectors. And I can't afford the ring flash or twin flash.
But I always like to try breaking rules just for the sake of seeing WHAT can be done. Even if it's not something that serves any practical purpose, it's fun to experiment.
So I recently did some plastic model photography using ONLY the FL-36R for illumination. The camera was the E-500 with the 50mm macro. You can see the set up. I made a simple, flash mounted auxiliary reflector from some plastic and bungee cord to give the front of the subject a little extra illumination. Then I just bounced the main flash off a piece of scrap styrofoam. I have to say, I think it worked just fine: