Change Your Life by the Words You Speak and the Thoughts You Have

And Yes we can control what we meditate on. 

Life and Death is in the Power of your tongue:    Proverbs 18:21 21Death and life are in the power of the tongue: and they that love it shall eat the fruit thereof.   

Speak your desired result over your life.

Visualize yourself being what you want to be or that which you desire to accomplish in life 

Proverbs 23:7 KJV 7For as he thinketh in his heart, so is he: Eat and drink, saith he to thee; but his heart is not with thee.  Whatever you meditate on will become you.