You will automatically qualify for your first masters when you win the amateur championship. If you win that one you also get the cheevo for that. For the remaining 6 just progress through your career normally. The only requirement for the masters is that you have to be ranked 99 or higher on the ea sports leader boards. So my strategy is to play all the 3 & 4 star events and that should keep you ranked fairly high. Just keep checking your ranking after every event so you dont go over 100. Playing the 3 & 4 star events is also a great way to work on your course mastery levels.
My first guide so please leave any and all feedback for help on future guides.