When making tacos from a box or mix, when you cook the ground beef throw in diced onion. It adds a little something extra to your tacos!! If you like green peppers add those too. Drain the meat, onion and pepper and add the sauce mixture and continue to prepare the way the directions on the back say.
Also, throw in a can of Rotel Chiles and Tomatoes. It increases the amount of food and spreads out the meat a bit further. I don't even bother to drain the can. I use the liquid in the can as part of the mixture for the taco seasoning. Kicks it up a notch! (as Emeril Lagasse would say!)