Before doing any esoteric work, you must shield and center yourself. Guarding against dangerous negative entities is paramount as is protecting yourself against psyhcic attacks. You will also need to put up a barrier when you fall prey to psychic vampirism whether or not the drainage of energy is intentional. Being calm and focused is most important in doing metaphysical work. Since there are myriad ways of shielding and centering, what works best for you is the way to go. I will go through some forms of shielding and centering here, and hopefully, some of them will spark some ideas for you.
Let's start of with the most common way of shielding and centering: visualization. For most people, this is the easiest way. You can visualize putting up a strong wall made from titanium, steel, iron, or any strong material. You can surround yourself with white swirling lights or see youself in indestructable armor. Use whatever materials you find to be the best barrier for you. Now for centering. See yourself as a very strong tree rooted deeply in the ground. Your roots are very healthy and are being nourished by the minerals in the ground. Now go slowly up your thick strong bark to where your first branches are. See how laden with leaves they are. Now slowly go further up to your canopy and see how rich it is. As you are going up, envision white light going from your strong roots to your rich canopy and back again. See your tree center, your solar plexus as you breathe slowly and deeply in and out. Do this until you feel centered; you will know when.
For those who do not find visualization easy, the auditory sense can be used very nicely. You can surround yourself with beautiful music such as Beethoven's Ninth Symphony or what music you find to be glorious. You can envelop yourself with battle type of music.or whatever music you find to be protective.To center yourself, hear yourself as a strong tree with deep roots in the rich soil. Hear your roots go deeply into the ground as you are being nourished by the earth's minerals. Hear your bark growing as you slowly go up the tree to the first branches and slowly up to the canopy. Hear the leaves whispering to each other as music of the spheres sings from your roots to your canopy. The music is deep at your roots and gets higher as it climbs to your canopy. Hear the mellow music at your tree center, your solar plexus. Hear your tree's breath as you slowly and deeply breathe in and out. Do this until you are centered.
Some people have a stronger olfactory sense so for them protective aromas are more useful. You could surround yourself with very strong skunk aroma. I know! I know! But the bad aroma may be just the thing to keep unwanteds away or you can permeate yourself with beautiful scents such as roses. Use those aromas you find to be the best way to drive undesriable entities away. For centering, smell the earthy scents of the forest. You are a strong tree within that forest. As you breathe, open your nostrils wide and take in the rich soil. Smell your roots deep within the ground taking in the plentiful nourishment of many minerals. Smell the minerals nourishing you from your roots to your center and onto your canopy. Smell the rich earthniess of your bark center, your solar plexus. Smell the sweet air swirling from your roots to your canopy and you breathe slowly and deeply in and out. Do this until you are centered.
Finally, there is the tactile sense. Feel the armor encasing you or feel the strong materials of walls surrounding you. Feel the coolness of steel or titanium encasing you or the hardness of a strong bivalve encasing you in a protective shell. Touch whatever is protective for you. To center, feel yourself as a strong tree rooted deeply into the ground. Feel your healthy roots being nourished by the many minerals. Feel the rich soil as your roots firmly take hold of the ground. Now feel your bark up to your first branches where you feel your leaves gently touching your branches. From there feel your bark to your vast canopy where you feel the air swirling down to your roots and climbing back up to you canopy. Go slowly down from your canopy to the center of your bark, your solar plexus. Here feel your bark contract and expand as you slowly and deeply breathe in and out.
I have just given you a few suggestions. which I hope have fostered some ideas for you. Again, you can surround yourself with white light. And you can ask angels to be with you.