I used both the draw it out on a sheet a paper, tap it out on the knees, Martha’s approach but using “nice cup-a-tea”, and the one other critical item is listening to recordings of a really good performer playing it, and after listening for a bit trying the tap it out along with that performance (while looking at the music) before trying to play it. It can also really help to get one of the apps that slow down music (anytune, musicspeedchanger, etc.) and play a long.
I found, after taking a workshop with Alfredo Rolando Ortiz, that really listening, listening and listening until you internalize the rhythm helps so very much! As well as playing it “slowlier” of course.
Thoughts from an amatuer.