Recently Mike made a post on his blog mentioning my post on shields, and there was some interesting commentary that occurred as a result about whether shields were really effective or not. Several people argued that while shielding protected you it also didn't allow you to interact with the world as effectively. Ananeal argued that:
Working shielded makes your magick less effective in terms of influencing material events. Even if you put up a shield that’s perfectly permeable to your own magical workings, which takes some skill, it still takes some of your energy/power/strength/whatever you want to call it just to maintain the shield.
He then proceeded to mention that he'd developed specific entities to take care of magical protection and that he also did a daily regimen of practices. The points that he and the other commenters made were valid ones, but I've never had any of the troubles with shielding that they suggest occur.
Like Ananael I do a daily practice. It consists of Tumo the raising of psychic heat, which I generally use to "wake up" my internal energy, and a combination of Taoist Water Breathing used to dissolve any internal blockages and the Zeroing technique that William Gray writes about in Magical Ritual Methods. There is a derivation of that technique developed by R. J. Stewart called the Sphere of Art. The zeroing technique involves creating a space of Zero Time, Zero Space, and Zero Event, essentially a space/time where nothing exists save the practitioner AND what the practitioner chooses to bring into that space/time. I use this technique with my magical work in general and it can, for all intents and purposes be considered a "shielding" technique.
Now when this technique is used it does serve to create a very specific space/time that excludes anything not brought into it by the practitioner. However the beauty of it is that you can bring into it exactly what you need to work with, be it an entity, possibility or something else. Additionally, what is also significant is that when you wrap up the magical working, and return that space/time to regular space/time, you merge it with and embody it into reality, making a seamless transition where there is no resistance to the possibility being manifested. That problem mentioned in the comments about not connecting to the world or being able to effect material events? Not a problem with this technique.You draw in the event you want to affect, as well as the possibility you want to use to solve the problem, work the magic and mesh it into your own identity, and then release the zeroing space/time, or sphere of art and allow yourself and the magic to fully reintegrate into the world around you, embodying a new reality in the process.
Back when I did shielding in other ways, I also had my shields set up so that I didn't have to maintain them. I let the influences, people, etc that were trying to interfere do the maintaining for me. Always worked like a charm and can be used with wards as well, when shielding a place. The shields only activate when something directs energy that would be harmful or distracting to the magician. And those shields are fed by the very energy, influence, etc being directed against them. Simple, effective, no draining of your energy required.
And my point in mentioning all this is simply that if you know what you're doing, a given act such as shielding shouldn't have any of the problems that the people mentioned in the comments. Defining a technique by its limitations means you accept those limitations and don't question them. While you should know what the limitations of a given technique are, define it in terms of what it could do and then experiment! Don't settle for explanations offered by others about the limitations and problems of a given technique. There's always a way to solve the problem or limitation of a given technique if you are willing to experiment. I only encountered those problems when I first started practicing magic and when I encountered them, I got curious and decided to see what I could to fine tune my shields and avoid the issues they mentioned in the comments. It took a bit of a work, but its nothing that anyone couldn't discover, provided they are curious enough and willing to experiment with a given technique. Why settle for allowing a technique to limit you? My answer: Don't settle...experiment.