It ain't just leaning..."...all you have to do is lean on the foot and you will go that way doesn’t seem to be working for me."
I think you're right, Ryel. If you just lean on the foot, without making any other movements to pivot the board or to change the edge angle, you will actually increase
the amount of friction between the edge and the snow at that end of the board--causing it to go slower. This results in the opposite of what you're trying to achieve.
To make the directional change on a falling leaf, you'll need to complement the subtle weight shift with a smooth movement to reduce edge angle at the tip or tail (torsionally twisting the board). This helps to release the edge at the tip or tail and will cause that part of the snowboard to slide downhill. To do it while on the heel edge, simply press down slightly with your toes on the foot you'll be leading with. On the toe edge, allow the heel on your leading foot to smoothly drop slightly towards the snow.
You can also make a smooth pivoting movement with your feet and legs, slowly sliding the leading foot slightly down the slope, to create a slight angle to the fall line. Combined with the aforementioned weight shift, you'll find the board will slowly and smoothly go in that direction.
You combine both of these movements (torsional twist and the pivot move) with the weight shift to perform a falling leaf. It also helps if you focus on making these movements smooth and gradual, rather than sudden and abrupt, as you first perform them. Increase the athleticism as you gain proficiency.
Hope this helps. Enjoy the ride.