Focus
I don't like the word Visualize cause when you Visualize that mean to imagine. So I use the word Focus.
To Focus First you have to Meditate First.
Then and think of you Dan-Tein being a ball of light.
Third Concentrate in the middle of you stomach or your navel.
Then Make a visual picture in your mind of energy coming from your Dan-Tein.
You should be able to see have your eyes close remember.
Then take that energy and move it around through your whole body.
This help you Focus or some people say Visualize.