When you're up in the air flying and the motor stops for whatever reason (and as long as your gears didn't lock up), establish a glide path or angle of attack of where you're gonna land. When you're comming in and get close to the ground, pull back a bit on the elevator and increase cyclic pitch. this will cause the helicopter to basically flare like an airplane and increase in cyclic will cause it to land gently, and help slow it down. Watch a few you tube vids on auto-rotation...you'll get the idea.