My main kicks are two fold. Mae Geri (front kick) and Ashi Barai (sweep)
Whenever they advance on me with punches, Ill usually fire off a lead leg mae geri and clip them as they come in.
If they advance on me with a kick, ill dash to the inside or outside of the kick (depending on what kick it is) and sweep the other leg, then move in with a punch when their on their back wondering what the heck happened.
I never kick above rib cage level, because its a bad thing to get used to, due to some times, in my organization, there is no head contact allowed. Sometimes they have full contact, sometimes they dont. I like my technqiues to be able to be used at any time. Though, depending on the situation, I do change my techniques, thought usually it stays the same.