Here is a shielding technique that a friend of my wrote. The first part shows you how to create a ball.
Basic shielding technique
For this you will use your raw will/energy/power. If you are unsure what this is rub your hands together quickly until they heat up. That 'heat' you feel between your hands is your raw will/power and what you will be using.
Sometimes it is easier to feel it as a ball first so I will start with that.
-Direct your power to your hand, or both if you prefer, and feel it form into a ball. You may feel weight, heat, tingling, etc; it is different for everyone as we all use magic differently.
-Now focus on an element, Air is normally easiest. Feel it around you then wrap it around your ball of raw will. Some people imagine it as they are rolling their ball in it, like you would roll a doughnut hole in powder sugar. Use whatever feels right to you.
-Now wrap a layer of raw will around that.
You can make as many or as few layers as you choose. Just remember that it is your energy/power you are using, you don't want to drain yourself.
Making a shield is basically the same. It is normally best to make it curved as that makes it harder to break.
-Create a 'bubble' of raw will around yourself (or whoever or whatever you are shielding).
-Wrap your chosen element around the bubble of raw will.
-Then wrap another layer of raw will around that.
You can mix elements as well. When you make a shield also visualize what you want it to do as you are creating it. Like for an absorb you would see it like a vacuum or black hole sucking anything that hits it up. Although if you use an absorb you will want to make sure it is the outer shield as it will absorb any shield you put on to of it. When your shield is complete it will become 'alive' in that it will move and spin around you.
You can layer as many shields as you want, although if you start feeling light headed I would recommend taking a few of them down. Depending on your power level and how often you are attacked, your shield can last for hours, days, weeks, months, even years. When it breaks, either naturally or due to attack, you will generally feel or 'hear' a pop.
You might want to create and break your own shields daily until you get the feel for what it is like both to create it and when it is broken.
Side note: If you are creating balls of 'fire' you will want to be very careful. Your fire affects the astral which can in turn affect the physical. If you set a tree on fire in the astral it will eventually die in the physical as well. The same will happen to everything else as everything that is physical has an energetic form in the astral as well. If it's astral form is destroyed the physical form will die as well. It won't happen overnight but it will happen.