Generally, I recommend marinading whatever you plan to grill from several hours to overnight. The best method is to place the meat into heavy zip-lock plastic bags along with the marinade, and place the bags in a bowl or other container and placed in the refrigerator until ready to use (no more than 24 hours beforehand). You should turn the bags several times while the meat is marinading.

FLANK STEAK MARINADE:
1/4 cup soy sauce
3 tablespoons honey
2 tablespoons distilled white vinegar
1/2 teaspoon ground ginger
1/2 teaspoon garlic powder
1/2 cup vegetable oil

SPICY SIRLOIN MARINADE:
1 lime, juiced
1 tablespoon minced garlic
1 teaspoon dried oregano
1 teaspoon ground cumin
2 tablespoons finely chopped canned chipotle peppers in adobo sauce
adobo sauce from canned chipotle peppers to taste

PORK MARINADE:
2 cups pure cane syrup
1/2 cup maple syrup
1/2 cup light Karo syrup
1/4 cup apple cider vinegar
1/2 cup water
2 tablespoons vegetable oil
1/4 cup minced onions
2 tablespoons chopped garlic
1 teaspoon salt
1/2 teaspoon crushed red pepper

SHELLFISH MARINADE:
Juice of three limes
Juice of three lemons
1/2 cup coco lopez
2 ounces tequila
3 tablespoons chopped green onions
1/4 cup finely chopped cilantro
2 tablespoons finely chopped red pepper
2 tablespoons finely chopped yellow pepper
2 fresh jalapenos, finely chopped
Salt and pepper

PORK RIB MARINADE:
1/2 cup whiskey
1/4 cup pineapple juice
3 tablespoons tomato paste
1/4 cup dark molasses
1/3 cup applesauce
1/2 cup brown sugar, unpacked
1/4 cup raisins
1 teaspoon lemon zest
Pinch cayenne pepper

ALL-PURPOSE STEAK MARINADE:
1/2 teaspoon meat tenderizer
1/2 teaspoon Accent
1/2 teaspoon paprika
1/2 teaspoon garlic powder
1/2 teaspoon lemon pepper
Vegetable oil

SPICY BEER MARINADE:
1/2 cup ancho chili powder
2 tablespoons paprika
1 tablespoon ground cumin
1 tablespoon dry mustard
1 tablespoon kosher salt
2 teaspoons cayenne
1 large red onion
4 cloves garlic
2 serrano chiles, chopped
1 bottle of dark beer
1/4 cup dark brown sugar
2 bay leaves
Salt and freshly ground pepper

ITALIAN MARINADE:
2 cups extra virgin olive oil
1/2 cup balsamic vinegar
2 tablespoons minced shallots
1 tablespoon minced garlic paste
1/2 cup chopped basil

ALL-PURPOSE MARINADE:
1/2 cup extra-virgin olive oil
Juice of one lemon
1 cup chopped fresh rosemary
2 tablespoon minced garlic
Salt and black pepper