

There are a few ways we do it in Chinese.
In mainland, people would sometimes just type the initials of the pronunciation of the character. For example, hhhhh (哈哈哈哈哈, hahahahaha), sb (傻逼 sha bi, dumbass). It can get out of hand for people who are not super familiar with their vocabularies (like me, a Hong Kong Cantonese speaker)
Alternatively, one can just use a different dialect/version of Chinese. In Hong Kong, we can have both written Chinese and spoken Cantonese mixed in the same message. We simply pick which one of them gives a shorter version of the word. For example, 回家看看有無撞其餘活動 ([Written] Go home and see [Spoken] if it conflicts with other events). Sometimes we even mix in ancient Chinese.
I explicitly command my brain to stop thinking. When something pops up again I would go “nope, you ain’t doing that”.
I would visualize something being cleaned up, like a whiteboard being erased, or turning screens off.