This is key for any good writing workflow. I think it was by Pages “07 or ‘09 that I first realized I could set a keyboard shortcut for each style on my document. I then moved this workflow to Word (it’s far more buried down, but the ability to set a shortcut to a given style is there as well).
One more tip: many of the times I previously find myself reaching for a mouse can be replaced by a ⌘F, followed by entering a piece of the text I need to move my cursor to and then, hitting enter. From there, it’s easy to navigate, select text, type or do whatever I need without ever reaching for the mouse. Also remember to use ⌥+arrows to move from word to word (arrows left and right) or paragraph to paragraph (arrows up and down).
As per @Synchronicity comments on making Word a minimalist text-first interface, they’re one step ahead from the comments we had in a previous @Bmosbacker thread on focus modes. And I dare say this step is definitely the is Writer fonts… they’re so gorgeous!