Bubba's Barbequed Skirt Steak
Try to find untrimmed skirt steaks in a sealed bag with the juices intact and trim them yourself as this maintains maximum freshness. Buy about 6 pounds of untrimmed steak to yield 4 pounds of trimmed steak.
The skirt steak has different types of fat and gristle on each surface. The rounder (top) of the steak has a more marbled type of fat that takes more time to trim. The (bottom) flatter side has a thin membrane. Using a small very sharp knife (I use a curved boning knife), take the knife along the top surface, trimming the top, thin layer of the steak to remove the heavier fat from the steak. There will still be marled fat remaining in the meat and this is ok. Turn the steak over and pinch the thin membrane upwards and run the knife under and remove the thin membranous layer.