Buy and install a truck cap --- a roof that fits over the top of your pickup bed. This will let you sleep comfortably even if the weather turns bad. The best truck caps for sleeping comfort are camper shells that have roof lines raised above the height of the cabin and provide windows that can be opened easily from the inside. Less desirable are truck caps with roof lines that sit flush with the roof of the cab. These provide less headroom.
To build a sleeping platform, raise the bed on a platform which will allow storage of gear beneath the bed. A simple platform is easy to build: Lay several pieces of 2-by-4 lumber across the bed of the truck, resting them on the rim of the bed. On top of the lumber, lay a sheet of plywood. You will need to use a saw to cut both the boards and the plywood to fit your bed. There is no need to attach the wood to the truck itself.
Lay a mattress atop the sleeping platform. An air mattress allows you to easily deflate and store it during travel. You can even buy air mattresses designed to fit specific truck beds. Instead of a mattress, a piece of thick foam over the plywood also works.
Wrap the mattress with sheets and blankets, or use a comfortable sleeping bag. Foam or inflatable pillows are a good idea, as they compress easily for storage when not needed.
Secure the tarp by tying ropes through the metal-lined holes, securing them to the truck frame. Stretch the tarp out and tie it to a nearby tree, or support it with tent poles poked through holes in the tarp. Lay the tarp across the top of your truck cap, extending at least 3 feet feet outwards. This will allow you to keep the truck cap back door or window open even during rainstorms. Keeping the cap open will also keep you more comfortable on hot summer nights.
