The clove hitch is the knot you tie when you need rope on a post right now. Two wraps, thread the end through, done. It adjusts on the fly and it never binds up, which is why it starts and finishes almost every lashing in camp.
It also has a reputation, and the reputation is fair. On its own a clove hitch is not a knot to trust with weight. Wind shake alone can work it loose. DJ from The Bear Essentials shows three ways to tie it and then, more usefully, the small changes that turn it into something you can rely on.
Where to Use It
Guy lines, trail markers, ridge lines and bundling. Anywhere the rope needs to be adjustable and nothing depends on it holding fast. Push the two wraps together and you can lengthen or shorten the run without untying anything.
Where Not to Use It
Do not hang a load off a bare clove hitch. When it appears in a ladder or a shelter frame it is doing the start and finish of a lashing, with the lashing itself carrying the weight. Add a half hitch or go to the constrictor when it actually has to hold.
More Knots
Pair it with the bowline for a fixed loop that will not tighten, and the half hitch for the finishing turn used in step 8.
If the load is going to swing or pull hard, a round turn and two half hitches holds better than a clove hitch. It is one of the seven knots at how to tie a knot.