I discovered that my feet really helped me to get a grip on understanding the cadence. Actually it came somewhat naturally when I started to play the smallpipes... while seated.
Typically we tap one toe or the other, and that happens in a very natural way, almost without thinking. If a player taps both toes, he or she will find that nearly all tunes fall into the familiar left-right idiom. With slip jigs, however, that natural left-right pattern goes out the window.
Try to get both toes going like this...
LEFT-right-left RIGHT-left-right LEFT-right-left RIGHT-left-right.
You'll feel clumsy at first because you'll have to think about it, but after a short time this, too, will become comfortable, then almost subconscious.