I lay pillows and blankets around the edge of the bed, so that if DD falls, at least she lands on something soft!

(Not that its happened, although once she climbed down on to the floor somehow - I left the room, while she was sleeping in the middle of the bed, then came back five minutes later to find her sitting on the floor playing. I didn't hear a thump or anything, and she wasn't crying, so I have no idea how she did it, but having the pillows there obviously worked.)