The common misconception about leg ties on shoes is that they should wrap and tie all the way up to the knee. This can be dangerous because as you walk, your muscles and feet need the space and leverage that leg ties don't allow for. Unless the ties are elastic and long enough to wrap several times around the calf before being tied comfortably above the calf, always tie the show ties just above the ankle.
Put on the shoes while sitting so that your knee is bent at a 90-degree angle; this is particularly important for shoes with heels as it keeps the foot and ankle at an angle that will affect the tension of the ties the least as you walk around. This isn't as necessary if the shoes are flat, but try to keep the foot in a position closest to what it is when standing and walking as possible.
Wrap the ties around your ankles so that they in front of the ankle before crossing again in the back. Each time you wrap the ties, they should be crisscrossing directly at the front and back of the leg. As you wrap around, do not wrap too tight as this will pull on the knot and untie it or make uncomfortable to walk. Continue wrapping around until there is enough slack to wrap around one more time and tie a knot. The last time you wrap around, it should directly on top of the previous time, so that they appear parallel to the ground.
Tie a square knot. If you want it to look like a bow, tie the loops for the bow after the square knot because the square knot is what you need in order to keep the laces from untying themselves and falling off. If you don't want the knot or tie-ends to show, before tying the knot, wrap around twice directly on the same spot and tuck the knot under the lower tie. This will work best if the ties are ribbons at least an inch wide. For extra assurance that the ties stay, tie the knot around the last two loops on the leg, securing them together.
Liberally spray the knot with hairspray. Your goal is let it soak through so that it stiffens the knot making it harder to come undone and helping it to stay in place. This won't have as much of an effect on leather ties as fabric ties, so make sure that you have a tie knot for the spray to reinforce as opposed to trying to make the spray hold a loose knot together.