Grounding and Centering
You may have noticed that you're feeling a bit tired/headache-y/irritable after practicing raising energy. This isn't uncommon, and it happens to all of us. (Even if we've been practicing for years.)
The best way to counteract this is to "ground" any excess energy. To ground energy means to send any extra energy into the ground, or to pull energy from the earth to replenish your own "stores".
There are many ways to do this, but sitting down on the ground, in a chair with both feet on the ground or standing straight up seem to be the most common methods.
Focus on the energy that you have in your body - but make sure not to accumulate anymore or to concentrate it any more than it already is. If you're feeling jittery or overwhelmed with energy, channel the energy down into the ground. If you're feeling drained, draw some out of the earth and into yourself. The purpose of grounding is to balance out the energy in you to where it should be.
Visualization can help with this; many people visualize roots from their feet into the ground or some other similar imagery. (Personally, I use an anchor, which has significant meaning to me.) Try a few different ways to see what works for you.
Another reason to ground is to bring your mind and body to the present. It helps you focus on what you're doing at the moment, rather than be scatterbrained and all over the place.
Centering is just pulling all of your energy to one place in yourself. It helps you focus. It is usually done when grounding.
When you feel your connection to the Earth, and your energy is all balanced out - focus on whatever the task at hand is. (If you're just grounding to get rid of excess energy and not to focus, you don't really need to do this step.) Set your attention to whatever it is you need to do or want. And that's essentially the gist of it.
Physical methods of grounding are eating something, jumping hard onto the ground, laying down for a couple minutes. Sometimes food and physical rest can be better than going through all the energy work involved in grounding.