Choose (one's) moment phrase
To make a thoughtful and prudent decision about the most appropriate time to do something. Sometimes said ironically to imply the reverse.
She advised me to choose my moment before asking mom for a few bucks.
Wow, You asked your boss for a raise when he was angry! You really chose your moment, didn't you?
By choosing your moment to confess your love to her, you are more likely to win her heart.
The verb "choose" must be conjugated according to its tense.
The origin of this phrase is not clear.