I have found myself in the bad habit of not measuring anything when I whip something up in the kitchen. That said, you might not want to try this if you require exact measurements.

Tomatoes
Green pepper
Cheese, shredded
Guacamole or salsa
Taco shells
Firm or extra firm tofu
Onion
Garlic
Cumin
White pepper
Cayenne pepper
Cilantro
Salt (optional)

~Chop the tomatoes and green pepper, set aside
~Shred the cheese if it's not shredded already, set aside
~Chop the onion and garlic, and crumble the tofu
~Heat oil in a large skillet over medium heat
~Put onion, garlic, and tofu in skillet, and add seasonings to taste
~Fry until cooked through or golden brown (whichever your prefer)
~Heat taco shells as desired
~Spoon tofu mixture into taco shell, put cheese on top so it melts
~Put desired amount of green pepper, tomato, and guacamole or salsa into shell

NOTE: I made hard shell tacos (which I hate, but I bought the wrong shells) so I used the guacamole to "glue" everything into the shell.