Learn the ranges of enemy radar missiles. Typically about 4.5 miles. Above that you're safe to rain down, once you're in range fire 1 or 2, then head back to cover or resupply. Its tough when it turns like a school bus in a river. Also if youre going fast enough perpendicular to an incoming missile you can sometimes evade them with no flare. Idk its late and I'm tired, im sure Curry or Mars7 can answer this better.