Regarding having etiquettes with the scholars, Shaykh ‘Umar Baazmool said:
“Deeming his knowledge, precision, and his opinion to be reliable. It is reached with reflection, pondering, the best opinion, and accusing oneself of misunderstanding.
He should not undertake refuting him or debating him before that. If he must do so, he does not precede until he has verified it, sought advice, and prayed istikhaarah.
Then he presents what he must to his shaykh with gentleness and manners without viewing himself to have any virtue since his shaykh has enough virtue in his knowledge and understanding to be able to realise what he has realised.”
Elsewhere he mentions:
“From their rights is reflecting upon their statements and ijtihaad without rushing to criticize it. How many statements of the scholars were criticized by some of the people and the criticizer had an incorrect understanding of their speech! How many have found fault with a correct statement, and his illness was a faulty understanding.”
[Taken from “Interaction With The Scholars” p. 77 & 84]