The silence exercise.
It may be the easiest exercise, and the most difficult at the same time.
Depends on your approach.
Those who have speech problems, or who speak a lot than they themselves think is unnecessary, they should try the practice of silence also a lot of the time.
Just sit with nature in a park or even rooftop, and be silent up to 60 minutes, that’s it.
The most simple exercise on earth, and the most instantly beneficial and worthwhile by all means.
It’s one of the greatest forms of meditation also.
Let your thoughts, fears, doubts, apprehensions and ideas come and go in your mind, freely.