There's all kinds of marinades for Skirt steak or 'arrachera', so I would suggest you try a few of them, make your own variations to taste then stick with the one you like. A good base marinade for 1.5 to 2 lbs of trimmed meat is as follows.
Cut steak into about 5-6 inch pieces, each piece should be about 1/4 inch thick or less.
Mix:
2-3 garlic cloves, peeled and crushed
1/4 teaspoon ground cumin
1/2 teaspoon salt
3 tablespoons fresh lime juice
1 tablespoon of soy or Worcestershire sauce
2 tablespoons olive oil
1/2 to 3/4 cup of medium or hot, fresh salsa or salsa from a jar like Pace (optional)
1/2 to 3/4 cup of beer, any beer with alcohol (optional)
1 shot glass of white tequila (optional)
Use the beer or the Tequila, not both
. . . Into a zip lock bag or tightly covered glass baking dish. A zip lock bag makes it easier to flip the meat over. Put in the refrigerator for 2 to 8 hours turning meat every hour. Discard marinade and put meat on grill at med to high heat. grill each side of meat 1-2 minutes per side or to taste. Cut steak while still hot into slices of desired size, the thinner the better.
Serving suggestions:
Of course warm flour or corn tortillas (fresh home made tortillas will make the meal unbelievable!!!), guacamole, salsa, 2 or 3 different types of finely grated cheese, grilled or stir fried sliced onions and bell peppers, refried beans and Spanish style rice. And last but not least, a cold beer or pitcher or Margarita's and enjoy. Getting hungry just thinking about it.
If you dont want the meat spicy leave out the salsa and you can just serve the salsa as a side dish.
