For years I have used this marinade. Kids come over and love it. I never measure and it is always good. This marinade came from a neighbor growing up. I must have told my Mom to make it. It is easy and always a hit.
cooking sherry vinegar
Equal parts are fine, more soy sauce is fine, more sherry is fine, less honey is fine. It always works. I grew up using this with flank steak. Now, we generally use hanger steak. Marinate all day. I put it in the frig in the morning in a large zip lock bag and take it out for dins.