An excellent visualization technique : If you are worrying about something, picture the words of your on a piece of paper.
Now ignite a match to the paper and watch the worry dissipate into flames.
Bruce Lee, the great martial arts master employed this mental control device regularly.
Get into the excellent habit of reading something positive and inspirational before you go to bed and as soon as you awake in the morning.
You will soon note the benefits as these thoughts will be supporting you throughout the day.