It's actually not as difficult as it may seem. Start by laying out the lights on the floor in a straight line, making sure to leave enough slack so they're easy to work with. Then, pick up the end of the string and begin wrapping it around the trunk of the tree, making sure to cover all sides as you go. Continue wrapping until you reach the top, and then plug in your lights to see how they look. If you need to, adjust the position of the lights to get the perfect look.