Here is what I use............

1 t. onion powder
1 t. garlic powder
1 1/2 t. black pepper
1 1/2 t. salt
1/4 c. soy sauce
1/4 c. Worcestershire
1/3 c. water 1/2 t. red pepper (optional)
1 basil leaf, crushed. (optional)

This is for 3 pounds of meat. I marinate overnight. The last batch was made with only half as much Worcestershire, as that's all I had. I couldn't tell any difference. I do not use the red pepper or the basil leaf, although I have eaten it with the red pepper and it wasn't too hot.