In Foxtrot - How as a leader to I let my partner know / feel that I am changing from SSQQ to SQQ and visa versa? Without using a set sequence of figures or verbal ques?

Larry

A slow followed by another slow does not rise, a slow followed by a quick does. Foxtrot overall doesn't have as much rise as the other dances so it's subtle, but it's still there.

Going forward, a slow that is followed by another slow has the footwork: Heel. Your toe will lower, but your heel will not begin to rise until after your other foot has passed the standing foot on the way to the next step.

In contrast, a slow that is followed by a quick has the footwork: Heel, Toe. We could already assume that the toe will lower, but this clarifies that the heel will then begin to rise even BEFORE the other foot passes that standing foot on its way into the following quick.

There are other elements to how you move as well... for example tango has no rise and fall at all, but still has both slows and quicks.

Another thing to think about: part of what makes a quick quick is that the following step is lead sooner than the step following a slow would be.