When DS was little, I would lie with him in teh crook of my arm and dress warmly if it was cold so I could push the blankets down.
When he was older, we'd sleep seperate from DH so there was more room, and he could just sleep nearby, clear of blankets & pillows. I don't think there's real need for special devices (a cot or something next to the bed might be handy if you're pushed for room in the bed, however).
Exacctly ythe same here with us..I did all of ther above, then we moved the cot next to the bed and left one side off, now we have the mattress of our bed on the floor, and if she rolls off it will only be on the floor from a small height so she wont be hurt, I always keeo the blankets down low and i snuggle down in them if i am cold, DD is in a sleeping bag so she does not need my blankets on her, DF only sometimes sleeps with us .Not once have i ever rolled on here or hurt her in anyway i always was scared i would but not once has it happened