In April I described, and linked to, a wonderful video, How To Think in English by Rachel Smith. (10-1/2 minutes)
In the course of researching "Placeholder Words" I ran across two, similar videos by the ever-creative Bob the Canadian:
5 Brain Games to Help You Learn to Think in English! -- Only 6-1/2 minutes long, this is not as comprehensive as Rachel's video but presents great exercises from Bob's unique point of view.
10 Fun & Crazy Ways to Practice English When You Are By Yourself -- Just over 11 minutes. Most of these exercises keeping your mind rolling in English with no time for your native tongue.
Bob expands on Rachel's idea of thinking in English just before bed so as to dream in the language. If your phone has the ability, record a summary of your day, then set the recording to be your alarm for the next morning.
One of the crazy activities is simply copying a story, a traditional writing exercise popular with the French and others. However Bob made a great modification. You read a sentence from the book (or article) in one place and run to another location to write it down. That way, you have to keep the words in your head for several seconds while travelling!
Since Bob demonstrated, using a long table, outside on a windy day, you will see that the challenge can involve physical exercise, too.