For me,your hands set up kicks, not the other way round.
This is true.
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.
Majority combos start off with the jab, cross, then finish with a kick or similar variations. Unless you quickly flick it, it's a lot easier to be telegraphed. When you're launching combos it's irrelevant cuz so many things are coming at you. I was sparring with an instructor and I got drilled over and over with leg kicks cuz he'd jab, throw a left hook, right, up down...up down...shit was confusing...but that's how you know it's effective. Also punches are used to create distance so your opponent is almost always blocking or at least moving out of the way to enable you to set up your kick.
In the end of the day you do what you want to do, but that's the basics. That's one thing I love seeing is crazy combinations.
Nate vs Wilson - he did like a Killer Instinct 10 hit combo
Anderson Silva vs Rich Franklin I (jab, cross, chopping leg kick, clinch knee of DOOM! Fawking vicious!)
GSP vs Hughes III (He throws the quickest superman punch and leg kick combo which he learned from Phil Nurse.)
Alex Caceres of all people threw one I learned...roundhouse, spinning back punch)
Stefan vs Miocic
Cung Le's jab, (fake back punch) spinning side kick to right hook is definitely one of my favorites.
Most fighters land two or three hit combos and that's about it. Mainly cuz it's pretty damn difficult to land.
Marcus Aurelius: Tell me again, Maximus, why are we here?
Maximus: For the glory of the Empire, sire.
Baked, not fried... the healthy choice.