Do yourself a mischief Australia British humorous informal
hurt someone or yourself
If you try to carry that suitcase, you’ll do yourself a mischief.
You'll do yourself a mischief if you're not careful with these scissors.
I would have done myself a mischief if I’d carried on wearing this tight T-shirt.
You'll do yourself a mischief if you don't calm yourself down.
Indicates that something which initially seems bad but harmless can become much worse in the future or lead to a harmful development
Starting of the idiom is a verb, we need to conjugate tense for the verb
Said when you are frightened to do something again because you had an unpleasant experience doing it the first time
After being cheated by her husband, Jane loses her belief on marriage and doesn't want to start any new relationship - a scalded dog fears cold water.