Here is an example of a shielding technique that has worked for me and those around me, or those introduced to it. It is also fine if you have your own technique but this piece is a guideline. An oval shape around you that goes beneath your feet is a common one, a 1/2 moon dome over you will not cover what is below, so be careful many make the mistake of only going to the floor, dark spirits or entities with no physical form know no boundaries like floors, walls or ceilings.
My own favorite is a cone shape wider at the bottom and narrowing over the head, but seal the floor first, I see a blue and white spiral coming up from the floor up to the head, word of warning if you see it and it stops or stalls somewhere on your body or the person you are helping, it means you or the other person is blocked at that energy center with this method of shielding, so it is not just a shield it is a scanner as well, you don’t want to shield in an attachment do ya? remove obstacle with blast of energy from the feet up and through the crown, and continue with spiral, the outside of the spiral I use contains fire which consumes those who approach too close, like an early warning system, which is rather effective for the few who have witnessed it close at hand. What you choose to put as a warning or non invasive alert is your own choice, it is only limited by your own imagination or belief in it.