good question! I would love to see if there are any other ways to approaching this...
For motions, I just break it down by hitting the first count together and then once that looks good, do the first two motions until it's consistent, then the first three counts, ect. Tumbling, I have them practice by doing hurdle round-off's to counts or just the first standing tumbling element. Lots and lots of reps where it's easier to create the muscle/brain memory when to start the sequence on what count - we spend alot of out early summer practices perfecting the easy skills with perfect synch so it becomes second nature (motions for jumps, preps, bump downs, extensions, pulling positions in the air, ect.)