Tighten the shoes until you can't turn the wheel, this will ensure that both shoes are centered and out to the drum, then back off until the wheel is free with no drag. then adjust until you have a slight drag. If you have brakes that have automatic adjusters, that's it. If you have manual adjusters, it would be best to check/re-adjust after a couple hundred miles, and then periodically adjust to take up for shoe wear.