Choose your tarp based on what you want to use it for. If using a tarp to cover an existing tent, it will need to be larger than the tent you intend to cover. If using the tarp as your shelter, a minimum size of 10 feet by 12 feet is required.
Set up your tarp at your campsite according to its purpose. If it is being used as a campsite cover, it needs to be high enough that people will not bump their heads and angled so that rain will fall away from the covered space. If using the tarp as your main shelter, secure the low part of the tarp facing the prevailing wind.
Tie your tarp with ropes securely, making sure that if ropes are tied to tent poles or pegs that the pegs are hammered securely into the ground. Each corner should be well fastened, and additional ropes or bungees are recommended in case of wind or bad weather.
Setting up a tarp in a basic lean-to fashion can provide an overnight shelter or an additional barrier from the elements for your regular tent. Tarps can also be used as ground covers to keep your bedding from getting wet and can be used to cover firewood as well.
Creating an "A" frame shelter with a tarp is as simple as tying a rope to one corner of the tarp and tossing it over the branch of a tree. Pull the tarp over the branch, creating your "A" frame, and secure the corners. Take care not to snag and tear the tarp during this process.