With this technique, I am going to show you how to create and maintain a 'safe zone' where no-one can attack you. Whether your enemy would try to attack you physically, mentally, emotionally, or psychically, you will be able to create a buffer which prevents him from following through on his intentions.
The first thing to know is that pure Power drawn directly from the Source can overcome any lesser influence. Your would-be attacker is most definitely a 'lesser influence'. The stronger your connection with Spirit, the closer you are to the Source of pure Power. (The Keys To Power Mastery System is an excellent guide to developing your connection to Spirit.) With this technique, you want your connection to Spirit (and its Power) to be stronger than that of your enemy.
But however strong your connection to Spirit is now, you can use it for some benefit. Sit quietly and relax your mind and body. Focus your mind on opening your spiritual connection and flooding your being with Power. As you collect whatever Power you can, think thoughts of safety and feel the emotion of security. Don't think of your enemy at this time. Continue to build your feeling of safety and security.
Once you feel as safe as you can, imagine a field of energy (a white light as the traditional literature suggests) surrounding you as far as you can see. Imagine that this field of energy is charged with positive, loving, and protecting qualities. Just as heat negates cold, and light negates darkness, this field of energy will negate the negative intentions of your enemy.
When you have the images all in place, affirm "I am protected by the infinite Power of Spirit! No-one can harm me. In fact, there is no-one who would even want to harm me. Everyone loves me, as I love everyone. Love is the true nature of my life, and is evident in everything that happens to me."
And to finish the process, imagine that person who used to be your enemy. Project love to that person, and eventually they will respond with love. And until they do, they will not feel right about trying to attack you. Your shield of protection is active and working!