I think the minority of SPS keepers feed their corals. Those that do use plankton cultures like Roti-Feast or small particulate foods like Golden Pearls. Turning off the skimmer for a while may increase the time the food is in the water, but I don't think many people bother.
I personally don't feed my SPS at all. With plenty of light and Ca, these things tend to grow like weeds without supplemental additives.