All of these skills are best started with the help of an experienced horse person to guide you along, but videos can provide useful preparation, extra tips, or refreshers.
This video does make an error in the direction of bandaging (it should be done, as shown, rather than as said, from the front, around the outside to the back, which is counter-clockwise on the left legs and clockwise on the right), and I prefer to overlap enough not to end up with an extra length of bandage at the end, but it is otherwise a very good demonstration of bandaging a leg. For shipping wraps, purchase a size larger for the cottons and allow the extra cotton to cover the pastern, and then leave just a little bit exposed at the top and bottom after wrapping as you would for a standing bandage (as shown in this video). As far as tightness goes, the bandage should be snug but you should still be able to insert a finger or two between the bandage and the leg.
Hunter Braids (Mane)
The tricks here are mostly to not use too much hair per section, to keep the braid straight while braiding, to braid each section to the same length as the others, and to pull the braid straight up with your pull-through.
It takes a lot of patience to learn how to braid a tail, so this one requires a lot of practice both to get the hang of handling all of those strands while keeping them tight, and also to take many small bunches for an elegant look rather than using more hair to get to the end more quickly.
This is a good overall video, but personally I prefer to overlap my strokes more to prevent lines, and I try to keep all electrical cords safely against the wall away from the horse's legs except for the small section that I need at any given moment.
For those who don't wish to do a full clip, the next video demonstrates very nicely how to clip lines, and it also provides an excellent demonstration of clipping smoothly with an overlap between strokes, and always following the opposite direction of the hair growth.