updated by @rene: 01/21/17 05:17:41AM
I know there is various forms of shielding and all are based on visualization. I know I out of instinct if I feel a force or energy near me or approaching and it is bad or oppressive I send out as you said 3D visualizations of arms or hands or whole body manifestations of my self. They appear as light "constructs" to me and I picture myself taking hold of or forcing them back or out much like a bouncer at a bar so to speak. I try to vocalize within or out loud my intent as to what I declare of them. Seems to work for me as well. I think it is just natural instinct of your gift to be honest.
Well shielding is pretty common. Most common technique is picturing yourself surrounded in a bubble of light. Then there are few other techniques. Now with that said the 3d thing I spoke of you are the only other peson I have ever met who does this besides me. LOL To be honest I thought I was the only one. When I first learned of shielding I thought to myself, "hmmmm if it is about picturing energy I can do this as well as an offensive form of defense if it is all based on picturing things in my head." I may be wrong since I know you now do it too but I think it may not be a common thing and others may do something similar. Why no one else commented whose to say? I am not sure. It isn't odd or weird that I know of. Anyways if it works keep up the good work :D Hone it, fine tune it, and make it a second nature so when in need it never fails. I imagine for each person it may be a little different but if something works and gets results go for it!