Visualization is a powerful way of improving any aspect of your life, simply because your brain doesn't know the difference between reality and fantasy. The brain loves repetition, so the more you do, think, or say something, the more ingrained it becomes. It's like magic, and the best part is you get to use your imagination and daydream just like when you were a kid!
Athletes commonly use visualization techniques to take them to higher levels in their chosen sport, there's a reason for this and research has been done to back it up. Practicing your jump shot on the basketball court is obviously the best way to make improvements, but the second best way is to 'play a movie' in your mind about you making spectacular jump shots while not on the basketball court.
Consistency is the key to improvement, and the more vivid you can make your 'movie' the better the results will be. For example, when I became interested in competitive bodybuilding my visualizations were difficult because I had never competed. So I did the next best thing, I went to watch a local competition. I paid special attention to the audience's reactions, the facial expressions of the competitors and the way they interacted with one another. I then added this new experience to my own personal 'movie'. My visualizations became more vivid as soon as I added things like what the temperature in the room would be like, the smell of Dream Tan and the sounds of people chattering in anticipation all around me. My confidence and familiarity with something I really had no experience with became more profound the more I practiced it.
It doesn't matter what you want to improve in your life, whether you want to have better relationships, lose weight, compete, run a successful business- whatever, visualization can help you get there. It's your time to have fun and play just like when you were a kid, so aim high with your goals and have fun!