Hi, my preference is to run a main ridge line across two trees and put the tarp over it and tie the corners to tree trunks (a little lower in height than the main ridge line).
Couple of things to note here:

1. The tarp should be big enough to cover a decent amount of living area in your site. I think I got a 12 x 12 from Canadian Tire.
2. First choose the two main trees that you are going to use to tie your ridge line, and lay the rope across the site, put tarp over it, and then raise the ends and tie to the tree trunks. The ridge line should be stiff.

The first response is good but in the event you don’t have trees in the immediate area you can use a stick or sticks or hiking poles about 6 feet tall to use as poles and run lines from the top and secure them in the ground with tent pegs. The other ends of the tarp can be secured directly into the ground using tent pegs.