Here's a triplet workout in 3/4, using 4-Way Coordination by Marvin Dahlgren and Elliot Fine. The idea is
fairly obvious, and has certainly occurred to a lot of people, but it might
help for me to suggest some parameters.
The complete workout may not be immediately attainable for everyone, and you certainly won't be able to do it exhaustively in one session, but any part of it you complete— even just a warm-up— at any tempo, will be an accomplishment.
Using 4WC, play each four-8th note pattern by itself, repeated, from these lines:
p. 4, lines 7 and 8.
p. 5, lines 3, 4, and 9.
p. 6, lines 1, 9 and 10.
The complete workout may not be immediately attainable for everyone, and you certainly won't be able to do it exhaustively in one session, but any part of it you complete— even just a warm-up— at any tempo, will be an accomplishment.
Using 4WC, play each four-8th note pattern by itself, repeated, from these lines:
p. 4, lines 7 and 8.
p. 5, lines 3, 4, and 9.
p. 6, lines 1, 9 and 10.