Bowline (a super helpful rigging friend)
So of the many knots you will use on a stage the Bowline is one of the most useful. It has the great ability to hold a heavy weight and then still be able to be untied easily. It has some downfalls as well. It does reduce the strength of the rope and it can creep rope through itself as it tightens. Overall it is a great knot and it is well worth learning how to tie it.
The critical part of the knot is the beginning. How you start the loop on the standing (long part) of the rope will determine how you tie the rest of it. Here are two examples of how to start the knot. Pay close attention to how the loop overlaps the end. This is where you screw the knot up if you do not go the correct direction through the knot.
From this initial twist with a loop you just have to go around the back of that vertical part of the rope and then back down through the loop. It sounds super easy but it can get confusing. Here are all of the steps involved in making the knot. Note how it should tighten up at the end with plenty of tail. The bowline likes to pull in some rope as it tightens so give it lots of tail so that it does not come apart on you. Also note this is tied with the orientation of the first of the loops in the previous picture. If you did the other orientation you have to flip some of the directions.
A few notes on what can go wrong. If you go the wrong way through the loop you will get what is shown on the first part of this image. You can tell as you tie it when the parts are parallel like they are shown. If you don't correctly go through the loop of rope the second time you will get the second of these examples. It holds but not as well as a correctly tied bowline. Avoid these and it will help you especially when it comes to untie it.
A few last notes. A bowline will reduce the strength of the rope to roughly 60% of what it was to start with. So rough figures would be to half the strength of whatever you are tying the knot in.
Good luck with this one it can take a bit to make it work out but it is well worth it.