Don't imagine a pink elephant!
...and now you're imagining a pink elephant.
We do not have direct control over the thoughts, images, ideas, etc. that present themselves to our mind. However, we do have a powerful way to impact the nature of our thoughts, inspirations, mental images, and general state of mind over time: we can ACT differently.
We cannot simply decide to feel awe, wonder, and reverence in the presence of Our Lord present in the Most Blessed Sacrament: but we can decide to bow deeply during the consecration and say the mental prayer "My Lord and My God!", with Thomas the Apostle, when the host is elevated. We can decide to attend daily mass whenever possible.
We cannot simply decide to adopt a life-changing habit of turning, many times each day, to Mary the Intercessor of grace and having recourse to her in all our needs and offering her regularly all our prayers, works, joys, and sufferings: but we can decide to pray a rosary every day, we can decide to pray the Angelus thrice daily, and we can decide to do the First Saturdays devotion.
We cannot simply decide to stop thinking all the time about food, or drink, or our physical appearance, our clothes, our money, what's on TV, what's on facebook, what's in my email inbox. But we can decide to fast, we can decide to abstain from drink, we can decide to throw away the mirror or the scale, we can decide to wear a scapular outwardly in public and accept the looks and the questions as an act of humility, we can decide to give away more of our money than we can afford, we can decide to throw out the TV, we can decide to get rid of our home internet if need be, we can do a daily examination of conscience, and we can confess our venial sins weekly.
We cannot simply decide to believe that God will really hear our prayers and intercede for us - but we can decide to pray as if we did believe it.
We cannot decide to be a saint, but we can, by the grace of God, decide to imitate the Saints.
This is the full meaning of "faith without works is dead": not that the lack of works is a sign of the loss of faith, but rather, that the works we do by the grace of God renew and create faith, and if we fail to do the works then our faith will wane.
This is also the full meaning of "I'm Going In!" If we want to engage in the invisible spiritual war that rages around us and have any chance of surviving, we must first go in...inside ourselves...and seriously examine the state of our souls...and start doing the things that will prepare us for the day of battle.