Is there a generally accepted method for lightening bread dough that is pretty general for a variety of breads; pizza crust, whole grain bread, dessert breads, etc.
Heaviness is caused by fiber and lack of water. A dry wheat dough will make a very heavy bread.
On the other hand a very wet dough that has a lot of protein will be lighter. The steam when baking will inflate the protein structure. The extreme example would be angel food cake which is light enough to not really be bread anymore.
Obviously you don't want it to be too light because then you get wonder bread. A lot of the things that make bread taste good also make it heavier.
The variables you can play with are: