This is a good multipurpose marinade for tougher cuts of meat (especially beef). Soak cuts like flank, skirt or flap for no more than 8 hours. Just a couple of hours will be enough.

1/2 cup Worcestershire
1/4 cup Soy Sauce
1/4 cup Water
1 Tbls. Red Cider Vinegar
1/2 Tbls. Lime Juice