Here is one technique to wrap your hands for boxing, as recommended by an instructor. You'll need a wrap that has a thumb loop and Velcro on the other end. While you're doing this, make sure that it's comfortable and not too tight.
First, stick your thumb into the loop and wrap around your wrist 3 times, tag-side down. Next, wrap slightly above your first knuckles 3 times while moving down toward your wrist. After that, wrap between your fingers up to your middle and pointer fingers. Wrap across the back of your hand again. While the wrap is under your palm, wrap between your thumb and pointer finger and over the back of your hand once again. Then, wrap around the top of your hand 3 times. You can finish up whichever way you want to the end of the wrap.