Something as simple as tying your hiking boots improperly can make a big difference when on the trails. Hiking boots are specifically made to support your ankles, ensure good tread and comfort for your feet while walking, and they are waterproof. Hiking boots come equipped with "D" rings to lace your boots in. Besides allowing some give while lacing, the "D" rings are designed to be easily laced even with freezing fingers. In addition to the rings, there are three metal hooks at the top of the boots. These hooks ensure extra support to the ankle. Tying your boots properly will help prevent sprained ankles and fatigue.
Stand the two bottom "D" rings up.
Pull one end of the laces through the both of the bottom "D" rings. Pull the laces through until there is equal amount of laces on both sides of the "D" rings. Pulling the laces through this way will ensure that the laces start "through" the rings as oppose to "over" the rings.
Cris-cross the laces and slide them through the next set of "D" rings.
Tighten the laces, slightly, as you pass through each ring. You want your boots to fit comfortably snug, but not tight.
Continue this until the laces have been woven through all of the rings.
Pull the laces together and cris-cross them. Turn one end of the laces through the middle (like you're simply tying your shoe, minus the bow) and tighten. This is called an overhand loop.
Pull the right side of the laces around the right hook. Pull the left side of the laces around the left hook. Tighten slightly.
Perform an underhand loop again, repeating Steps 6 and 7 until the laces have gone around each hook.
Perform one last underhand loop; this time, tie off the laces into a bow. Double-knot the bow to ensure the laces stay knotted.
To see what this looks like, visit: http://www.hitthetrail.com/boot_lacing.php.