There are no tricks an tips to get master qualification. Mturk administration team will decide the qualification it depends upon your completed hits with various requester and high approval rate. Do as many as requester's hits with excellent approval rate.
can you tell me how many approval rate or % required? i have... HITs Submitted 7492 — ... Approved 7076 99.2% ... Rejected 54 0.8% ... Pending 362
Amazon will not publicly say what is needed. That is why so many Turkers are frustrated with Amazon over this qual.