I thought this would be a good technique for those who are new to use during a time they feel that they are in danger from another caster. Please keep in mind that this is just how I use the technique and certainly is not the only way of protecting yourself. It does require meditation and visualization skill, the stronger the better. No other tools are required unless you feel it necessary to serve as a tool to help your focus.
1.) Find a quiet place and sit comfortably. Take a few deep breaths to calm yourself, breathing from your diaphragm. Relax and take some time to reflect on being the one still point of a world constantly moving. You are in control of your reality, everything else are just pieces that you can move at you will. Hold this belief deep in your heart and know what you are.
2.) Visualize a square outlined around you. Squares are stable shapes and have proven effective for protection in my experience. The outlines could be made of light, metal, or whatever feels solid for you to image.
3.) Visualize a large standing mirror emerge from the ground from each side of the square one at the time. Visualize the mirror as solid as you can with the intention “Whereever I go, may any malice from the (said the direction it is faced such as north, east, west or south) directed to me be reflected back.” Do this for each mirror, seeing them fuse together into a box with no cracks. You can also put a mirror above and below yourself to create a cube.
4.) Go on with your life and leave any fear of harm behind you.
To remove this shield, go back to step one and repeat the process, using the visualization to deconstruct the shield by seeing it slowly collasping into the square outline and seeing it disappear. Shields can be strengthened by either repeating the building process or tearing down old shields to establish new ones as it feels necessary (I usually do mine once a week).
An important note: shielding using mirrors can cause all energy, good and bad to be reflected away from the individual, which is why the intention I mentioned behind the shield is very important. If your intention is to block all forms of magic directed towards you, you will need to remove the shield once you feel safe, which can cause an opening if spirits are involved by your enemy. You can alter this technique using glass or diamond walls to cause the same effect if you prefer. I hope you find this useful