In a large pot, brown the ground beef, until cooked through. Drain any excess fat. Add the refried beans, tomato sauce, and seasoning to the meat; stir to combine. Evenly distribute about 1 cup of shredded cheese into the bottoms of the taco shells. Spoon the beef mixture over the cheese in each shell.
Place the filled shells into a 9x13 baking dish. (If you have trouble keeping the taco shells upright, you can ball up a small amounts of foil and use them between every other taco for support.) Then top with the remaining 1 1/2 cups of shredded cheese.
Bake for 10 to 12 minutes, until heated through and cheese is melted. Top with diced fresh tomato, lettuce, green onions, sour cream, salsa, or whatever else you like on your tacos!
Notes
I like to double the recipe - use 2 pounds ground beef, a full 16-ounce can of beans, an 8-ounce can of tomato sauce, and 1 ounce taco seasoning for the meat mixture. Then use half of it for the tacos and freeze the remaining half for another time.