Personally I've never understood why anyone would buy sprouts. They're easy to do, and, by doing your own, you have a much wider selection. For instance, I've never seen commercial sprouts for: broccoli; radish; fenugreek; and a whole host of others. All of the greens, for instance, can be sprouted, as well as grains and grasses.
Years back I made some permanent jar strainers by epoxying screening to the inside of a jar ring. Not too much later somebody introduced a plastic version of the same; and there went my chance at fame and fortune.
Anyway, my procedure is to put the seed in the jar and cover with warm water. Let it stand at least five minutes. Then pour it out. Do this two-three times a day until sprouting begins. Then just pour water in and out, twice daily.
Shel: As an alternative, you can grow your own micro-greens by actually planting the seeds. Use those shallow plastic trays that meats and other grocery stuff comes in. Using a hot skewer, melt some drain holes. Then fill with potting soil. Broadcast the seed over the surface, press it in, and mist with water. Cover the tray with cling film until the seed starts to germinate. Uncover, and put it under a flourescent light fixture, keeping the lights no more than about 2" from the growing plants.
By setting up these trays on a succession-planting basis, you can have micro-greens on a steady basis. And if you think store-bought sprouts are expensive, go check those baby greens.