We have a flat screen LCD TV and we leave it in the orginal carton it came in and simply lay it on the bed. There is a wall at the foot of the bed which will stop the TV from moveng forward under hard braking. The TV travelling position is directly over the wheels, so any bouncing caused by bumps will be minimised as well.
Ditto for storing it on the bed under the pillows we still have the box it came in but I don't worry about putting the TV in it I just put it straight on the bed. Our single beds are at the front of the van with a dressing table between them so even under heavy braking it can't really go anywhere maybe if I was going off road I may use the box as added protection. We also put the glass microwave dish wrapped in a tea towel in the magazine pocket on the wall holds it very nicely and isn't going anywhere.