Know what you're trying to do before you do it. Turning knobs at random isn't enlightening any more than throwing paint at a wall blindfolded will let you paint a nice picture.
“It may take practice to think more positively and more compassionately, but just as you must train a puppy to behave the way you want it to, you must train your mind to behave itself. Otherwise, like the puppy, your mind will just make a lot of messes.”