A few things I've learned from people on this forum. If possible work belly to one ring, make recurve area thin enough so wood doesn't get overstressed and crack, soak overnight & boil 45 mins to an hour, bend as soon as removed from boiling water, and bend in one smooth continuous motion. The next day I go back and set the curves with dry heat. The last 2 bows I've done this way and neither cracked without using a metal band like I've done previously. I also think making the limb as thin as you can get away with also helps.