Verb
make haste slowly (third-person singular simple present makes haste slowly, present participle making haste slowly, simple past and past participle made haste slowly)
(idiomatic) To do things in a deliberate manner to reduce mistakes.
It's a bad habit, I know, but I believe that you shouldn't do anything in life until you're ready. Half of life's heartaches come from decisions that were made in a hurry. One should make haste slowly. Marilyn Monroe
"Better to make haste slowly than not at all,” said Amnir sententiously. Leigh Brackett