My personal favorite combination.
Teriyaki Sauce:
1 Mix all but cornstarch and 1/4c water in a sauce pan and begin heating.
2 Mix cornstarch and cold water in a cup and dissolve. Add to sauce in pan.
3 Heat until sauce thickens to desired thickness.
4 Add water to thin if you over-thick it.
Let you chicken rest in marinade for at least 1 hour, but overnight preferably.
Grill chicken on direct heat for 4-5 minutes on each side, and then transfer to indirect heat until done.
Use a meat thermometer, or else be sure the breasts are no longer pink inside.