You should do this ideally when you have some time along, without any chances of being disturbed by outside sources. The area you choose to do this on, should be the area where your altar is located. Close the door and cover the windows, simply relax.
Get a candle that you find to represent you. It could be one of your favorite colors or simply one that when you pick it up you feel something special, it just feels right.
Take the candle and sit in a comfortable position on the floor. Put both of your hands around it, holding it in your lap. Clear your mind of all thoughts. Now just slow down your breathing, by taking deep, even breaths.
Once you feel relaxed, think about your past and your present. As you recall it, visualize each thought you have going from your mind, on to your hands and finally, into the candle. If it helps, just visualize a stream of energy going from your head all the way down to your hands, like a river doing its course. Focus on this for as long as you need, you'll know when you've put enough of yourself into the candle.
Now place the candle in a candle holder and set it on your altar. Light the candle and turn off the lights, close the curtains, and create a dark room. This dark room represents the clarity of emptiness, and the candle represents all that you are.
Focus on the flame, feel the magick filling the room and yourself. Think of everything sacred and believe you are filled with magick. Build the belief until you have no doubt about your ability. When you are done, you may snuff out the candle.
You can repeat this process at any time you feel the need.