I'm not sure what's normal for how kids like to sleep. I thought a bed.
Since about July, Bella & Ben have been sleeping on the floor of their bedrooms (only sleeping in their beds a small handful of times).
Now that Finley's on the move... I put him to bed on his back - with his head on the left (the head of the bed)... And whenever I come back in he's done a 180* and is on his tummy.