TenOC is the way my grandmother made it, except we do include one egg.
For the RV, I buy the Martha White Cotton Country cornbread mix and follow the instructions on the back, adding the egg and using warm water. I add one tablespoon of self rising flour. One pkg is enough for a small iron skillet. Heat iron skillet and oil or bacon drippings on top of stove. Pour in batter and bake per instructions on back of package. For home, I use this recipe except instead of cooking spray I use oil or bacon drippings in the iron skilled: http://www.marthawhite.com/recipes/southern-cornbread-2630
Some more great recipes: http://www.marthawhite.com/recipes