First off visuallizing is seeing and feeling images in your mind and putting them to use in and on the physical plane on which we live. Although it sounds complicated we really have done this at some point in time for example: daydreaming.
Gather Energy on The Inside And Out
Close your eyes, hold your hand out trying to keep it straight while also stiffening it into a fist. once your hand stops shaking and feels like its going to break (or maybe not), visuallize the energies in the air getting pulled into your palm. once you feel you've collected enough energy close your hand tighter and tighter but don't close it. then bring that hand up to your mouth, open your hand just a bit, then bite upon the energy, chew it tasting the different flavors, swallow, and repeat (bite, chew, and swallow) until the energy is depleted. this helps build up internal energy as well as lets you radiate more energy within your aura's
Meditate & Visuallize
Before you visuallize focus on these 4 main points in the structure of the barrier: has to be strong, doesn't solely rely on your energy but also uses the energies around you, can protect a large area, has to be a three-dimensional shape (I recommend a sphere). First I visuallize the 3D shape beginning to forn about as deep inn the ground as the height of the room you are in (can be a rough estimate), then continually build up in layers with the energy stored on the inside and outside of you once the roof of the barrier is complete.--> See PART III
To seal the barrier you will need to (put simply) point at the roof of the barrier and draw a "Star of LakShmi" (A square on its side and a square on its corner overlaping inside a circle) or as I like to call it an "Octagram" (http://en.wikipedia.org/wiki/Star_of_Lakshmi) you will want to either use your hand/arm or something with a "reach" to do this.
So this is a one time thing to start out with... Basically you visuallize a doorway only human beings can go through, visuallize other things trying to get through and failing.
There you go I hope this helps all of you who look for simpler and/or new and reliable magic
Best of Regards,