OK, it sounds like an obvious question (I know how to turn the flash on), but now that I have a camera with built-in flash, I'm wondering how to best use it? Before now I had the E-M5 and E-PM2 and didn't bother ever attaching the external flash. I've always just used the available light when shooting my pictures. Can anyone give me some tips on how they use the E-P5 (or any of the camera) flashes to improve their photography? I'm curious about indoor group/portrait shots, or fill flash in backlight conditions, etc. Any firsthand experience or pointers to any tutorials would be appreciated. Thanks!