The Taut Line Hitch is the best knot for camping and the only knot you need in most situations. Its easy to learn, easy to remember, easy to tie and easy to untie.
This knot has a special feature: you can slide it up and down to change the length and tightness, (taut means tight) between the two objects it connects. If you have cords coming from a tarp or tent that attach to a tent peg or a tree, each cord has to be adjusted to keep the tarp or tent from sagging. That's what the Taut Line Hitch does best. It was invented by some nameless human way back along our trail and we can share in his brilliance by learning and passing on his insight, which goes from you, (as soon as you learn this knot), back to me, back to my patrol leader in Boy Scouts, to his teacher, down along the chain of human cleverness back all the way to the inventor of the Taut Line Hitch. I wonder how far that trail goes. How long after the invention of cordage did the idea of a knot so versatile pop into his head? It is fun to ponder our connections. Glad we're clever and willing to share. (That's why I love this website, so much fun to learn and share.) So learn it and teach it to someone and then say, "I just taught you the Taut Line Hitch."
Have a close look at the knot before trying to learn it. We see in the picture two Taut Line Hitches, one near the tarp and another connecting the tarp to the tree. We'll untie the one nearest the tree and retie it.
Wrap the cord around the tree and you'll see one part of the cord is straight and the other end is the one you can twist around the straight cord. Take it slow and let your eye follow the cord as it forms the knot in the pictures and it won't be confusing, it will be simple. It will probably help if you watch the video I made, (these pics are screen captures from that video), and its easy to learn the Taut Line Hitch if you can see it tied while I tell you what I'm doing.
Wrap the end of the cord around the straight part of the cord between the tree and where the cords cross. Do this twice so you end up with 2 loops around the straight cord side by side and nearest the tree.
Now wrap the cord around the straight cord again, but this time do it on the opposite side of where the cords cross. This will give you two loops near the tree and one loop closer to the tarp. Then snug everything up. (It wasn't easy the first time you tied your shoelaces but I guess you're pretty good at it now, so be patient and practice the Taut Line Hitch and you'll see how easy it really is.)
To loosen or tighten a Taut Line Hitch, hold the straight line, grab the knot and then slide it along the straight line. Unless you're holding the straight line still, the knot won't move. Very cool!