For me,your hands set up kicks, not the other way round.
Thats good general kickboxing advice.
But its not the be all and end all. There arnt many fixed rules in fighting.
Hendo wouldnt land his H Bomb so often if he set it up with a jab rather than his lead round low kick.
A classic combo in kickboxing is push kick jab cross
There are many combos that start with a kick first and its wise because from the outside where you all start kicks out range punches.