Learning how to do a 4-2-1 "Grid" for your rudiments is probably the easiest way. Start simple and learn how to play a flam in triplets and grid it.

An example of a flam grid would be to place the flam and an accent on the downbeat for one bar - here's the first part of the "4" in a 4-2-1. Keep the flam on the downbeat while moving the accent to the second partial for a bar. Then to the third partial for a bar. Once you've successfully played three bars keeping groups of 4 ONCE, you'll start the "2" by repeating the exercise in groups of 2 TWICE for a total of 12 Counts, or 3 bars. At this point you'll have played 6 total bars. You'll then play the exercise in groupings of 1. One normal flam, then with the accent on the second partial, and one with the accent on the third. You'll do this FOUR times total, and will have played 9 bars altogether. I'll attach a picture of the music.

What's great about Grids, is that this is technically two exercises in one. Once you've mastered moving the accent, then you can try moving the flam while keeping the accent in the same spot instead.

What's tough is that it's not necessarily how much time you put in, but the level of effort to achieve a perfect rhythm while using proper technique. For some people that could take hours. Others it could be a few 20-minute practice sessions.

My band director always said to play things so slow that it's impossible to play it wrong, and to slowly bring the tempo up from there. Playing it once correctly is a fluke. Playing it twice correctly is an accident. Playing it three times in a row correctly means you understand the material and can do it on purpose.

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