The "wrap 3, pull 2" has long a preferred anchor method with rescue teams and others who need a super strong anchor, but this Crafty Rope Trick (CRT) can also be useful for recreational climbers.
As it takes a few minutes to tie, it’s not really feasible to use it regularly as part of snow or rock pro. However, it can be useful when setting up top ropes in an instructional setting, making a rappel anchor, or pulling your car out of a ditch. All you need is a long (9+ feet) length of webbing.
Note that you cannot make this anchor with a sling that's sewn into a loop. You have to have a single long piece of webbing.
To make this anchor, make three wraps with the webbing around a large solid object. In many cases this will be a tree. Tie the free ends in a water knot with at least 2 inches of tail on each side of the knot. Now, pull the two strands of the webbing that do not have the knot in them, leaving the actual knot against the tree. The knot, normally the weakest part, is isolated by the friction against the tree and has minimal load on it. Four strands of webbing share the remaining load. This makes it super strong.