Scoop the sour cream into a bowl and add the packet of tacos seasoning. Stir to combine.
Lay out all 14 tostado shells. Spoon refried beans on two tostadas, spreading to flatten. Spoon guacamole on two tostadas, and flatten. Spoon the sour cream sauce on two tostadas, followed by the pico de gallo on two tostadas. Repeat with the cheese, green onions and olives.
Then place the bean tostadas on two separate plates. Stack them with the various tostadas until each stack has seven tostadas with seven different toppings. If you have any sour cream (or sour cream sauce) left, add it on top, then drizzle with Old El Paso Taco Sauce.
When ready to serve, press a chef's knife down into the center of the stack a couple times to break up the tostadas. Enjoy!