2) Raise it up
"Floor space" is at a premium when truck bed camping, so consider building some type of sleeping and storage unit. I know a professional bass angler who sleeps in his truck bed while still hauling enough tackle to stock a sporting goods store. He does so by sleeping on top of his tackle on a raised platform made of 2-by-4 lumber and plywood. The platform is about 18 inches tall and fills one-half of the bed. An air mattress on top makes his sleep more comfortable, while open sides allow access to gear stored underneath. On the opposite side, he slides in totes, gear bags and other equipment. In my truck, I opted to build a plywood storage unit that spans from one fender well to the other. On the left side of the storage unit is a full-length divided drawer where I store ammo, roadside emergency equipment, a tool set, gun-cleaning supplies, a first-aid kit and other essentials. The right side is open and is where I slide in gun cases, extra boots and other long tools. In the spaces in front of and behind the fender wells I stash jugs of water, a lantern case, a camp chair and muddy boots. A self-inflating foam mattress pad goes on top. Commercial storage options probably are more convenient, but mine was much cheaper.