打腹稿

dǎfùgǎo ㄉㄚˇ ㄈㄨˋ ㄍㄠˇ

    • to work out in one's head what to write or say beforehand

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
to draft in the belly
Meaning
To work out in your head what to write or say before doing it. Neutral.

Sources