I’ve always hated flashes. I don’t like them flashing in my eyes, I don’t like the washed out look they give to photos, the unnatural light, or the sight of dozens of them flashing at events.
The practice is simple: Make your camera as sensitive as you can get good result, open your lens to its widest possible aperture, and then control the shutter speed to get the light level you want to use. You will almost always need a tripod to prevent camera movement while the shutter is open, and you will need to select subjects that are not moving relative to the camera. Shoot in RAW format, and use auto-exposure bracketing to take multiple shots with different exposures in rapid succession to be sure you get the right shot every time.
(Go read the whole thing over at TheGadgetsPage.com. It is short, sweet and worth it.)