The key one I always do is: Jab, reverse punch, kick to the mid-section. I might occasionally try a feint, but I figure 2 punches is an already enough feint.
Other ones I enjoy:
step forward front kick, step forward front kick, then crescent kick (the opponent may figure out the pattern so the crescent kick is more of the "hidden kick")
feint punch, takedown (kind of like how Matt Hughes used to do)