While it's a myth that marinades penetrate deep into meat (they mostly remain on the surface), they're still excellent flavor enhancers. Toss your steak in a marinade, like lemon and garlic or a basic balsamic vinaigrette, while you cut vegetables and then throw everything on the grill. You can also tenderize your meat in a marinade with ingredients such as pineapple, which contains an enzyme that breaks down meat's tough fibers over time. Use Food & Wine's guide to marinades for recipes with all of your favorite flavor combinations.