My sister used a rolled up hand towel that we taped into a log. so it would stay rolled up, She placed it on one side of her son and the other side he was up against the side of the bassinet. It was netted sides.
But he was determined. Hr squirmed and grunted into all sorts of positions.
Our daughter was rolling over pretty fast on her own. (she lifted her head when first born and i announced her name!)
. But during the day while she was awake, we would "help" her roll from her tummy to her back.. Just to give her an idea of what it should feel like.
we also did tummy time so she could strengthen her neck even more. We would place her on her tummy and lay down on one side, calling her name.. so she would look at us. Then move to the other side and call her name.. She would lift and turn her head.