all right, i now that every single being has is own energy, and that we humans have that kind of energy too, but my question is what can i do to collect that energy, to cast spells???
through meditation??
Well, meditation is a start, but then you have to focus your energy. I suggest you read about different techniques for focusing energy and try them out, then use whatever works best for you.
Centering and grounding can help draw in energy. And if you're at all into hermetic/ceremonial magick I'd suggest the Qabalistic Cross.
Here's a simple method for centering and grounding. It's not the only way out there, but it's the one I've had most success with. If it's not that great for you try googling "grounding and centering" to find a few other methods.
Centering
Calm yourself and breath slowly and evenly, and you may wish to close your eyes (it helps me). Take a deep breath and mentally follow it down into your chest. Breathe out, but keep your focus there. Take another deep breath and follow it even further down into you. Continue doing this until you feel like you may be in your energetic center. I unfortunately can't think of a good way to describe what this feels like, but if you think you're there then you're probably right. This energy center is usually somewhere near the belly button, but it can be a little higher or a little lower (mine is pretty low at around three inches below my navel). Once you've mentally followed your breath to this point, just stay there for a while.
This will pull in your wayward energies and focus them together within you, hence "centering." It can also help with feelings of confusion or being mentally scattered.
Grounding
Once you're good and centered, take another deep breath. Just as you followed your breaths to your center, follow this breath past the center and down out of your body and into the ground. Some people like to do this standing and have it go out their feet, but I prefer to do it sitting and have it go out my spine. Continue to do this, going deeper and deeper into the ground. Like centering I can't really describe what this feels like, but it's a pretty distinct sensation and you'll recognize it with time.
This connects your own personal energy to the energy of the Earth. Through this connection you can ground (send away) excess energy or dirty energy and you can draw in fresh energy. I'm going to warn you though that I experienced a sort of mania the first few times I did it. It appeared to be caused by the sudden rush of energy available, a little like an oxygen high I guess. It went away quickly and it only happened the first few times I tried it, but I thought you should be warned.
The Qabalistic cross is typically done as part of the LBRP - before to charge the spell, and after to fill oneself with balanced energy. I have no idea if you're into hermeticism at all, but here's a handy link with the Qabalistic cross and the LBRP explained; http://www.kheper.net/topics/Hermeticism/LBR.htm
