Proper Order to Incorporate Ingredients in Pound Cake When making a pound cake, this is the usual order I use:

(1) Cream butter
(2) Add sugar and beat it in
(3) Gradually add eggs and beat them in
(4) Gently fold in flour, alternating with liquid (if there is liquid in the recipe)

I would like to try separating the egg yolks and whites. In what order should I then add the ingredients? Please include an answer for recipes with and without liquid.
What you're probably looking for is a hybrid between your pound cake and a seperated sponge cake, in which you'd probably want to cream the yolks, butter, and sugar, mix your egg white foam with flour, and then fold the flour/foam into the yolk/butter/egg mixture. My gut says the amount of butter in a pound cake will kill the foam structure of the egg whites immediately, but what the heck... experimenting is always fun. 

Another option would be to make a regular separated sponge cake, and then use melted butter as kind of a soaking liquid like you would with a genoise. Might provide the fluffier, yet super buttery texture you're looking for. You could also just make genoise, but it's certainly not as rich as pound cake.