Thats good you are practicing. Do you take lessons or have a barn near you that can let you practice and show you?
I found this, I don't use the duct tape though, my wraps have no velcro so i tuck it in smoothly.
Rewrap the polo wraps if they are brand-new. Most new polo wraps are sold tightly wrapped with the Velcro closure on the outside. Before you can apply them, they must be reversed and rolled so the Velcro is in the center.
Check the wraps to make sure they are clean and free of any debris. In temperate weather, most polo wraps can be used a few times before they require washing. However, because they are made of fleece, they tend to attract dirt and debris (such as foxtails and other burs), which should be removed before reuse.
Start wrapping in the middle of your horse's cannon bone. Wrap clockwise on the right legs and counterclockwise on the left legs; this way, the bandages push the tendons toward each other. When your horse moves, his tendons will not pull against the wraps. Wrap down the leg, overlapping the previous wrap halfway each time you spiral down the leg until you reach the fetlock. Make sure to smooth the wrap as you go, so it is wrinkle-free.
Hook the wrap down around the back of the fetlock, across the horny growth behind the fetlock known as the ergot. Then continue spiraling up the leg. If done correctly, when you start the upward spiral, the wrap should form a small upside down "V" at the front of the fetlock. Wrap upward until just below the knee in the front legs or the hock in the hind legs. You may have a little extra wrap when you get to the top of the cannon (depending on the length of your wraps and your horse's size), so just make an extra spiral, completely overlapping the previous spiral.
Secure the wraps with a piece of 6-inch duct tape placed over the Velcro closure. I don't do this but there is nothing wrong with it.
Repeat the process on your horse's other legs.