This may sound strange but by far the best enchant a lock can have is run speed to boots. This gives them a slight increase in the speed they run, but it makes a huge difference. By boosting your speed even just 10%, you can not only keep an enemy from ever hoping to catch you, but put distance between you. This is the key to successfully using kiting techniques.
This enchant can be somewhat expensive, and it is a real pain to have to re-enchant each new pair of boots you get, but if you can afford it, it's very well worth it. I use them on my lock and it's a very rare thing for an enemy to even touch me. It allows me to kite them safely without fear of being caught. I will explain more about kiting later.