Over the course of the last four years, my writing has significantly improved. When I glance at some of my early drafts from back then, there can be no doubt about it.
My first novel (which was eventually cleaned up with the help of an outside editor) was almost laughable in it's first incarnation. How many times per paragraph was I using the word "that," for example?
Honestly though, the first draft of each novel probably hasn't improved tremendously over what I was able to produce back then. It's the editing that's better. I catch and fix the a myriad of errors during the editing process.
Which makes the first editing pass (the one immediately after writing the first draft) particularly burdensome.
Right now I'm trying to plow my way through "Supply Chain." Been working on it for four weeks, in fact. My normal procedure would be to do a fast read of the paper copy of the book, noting down the big picture items -- things like plot holes, unclear motivations, inconsistencies in a character's behavior, etc.. Then I would go through the detailed text line-by-line on my computer, taking out the spurious "that"s and the other obvious wording and grammar mistakes, along with other. I never get them all, but can probably cull ninety percent at this stage (and introduce an additional ten percent in the process).
Unfortunately, I'm seeing too many errors in "Supply Chain" to use this method. Instead, I'm bogged down in the paper copy, noting corrections to pretty much every sentence. It looks like a pen exploded on each page! This is effectively doubling the time it will take to complete the edit. I realize this, but the glaring mistakes are so distracting that I just can't force my way through the draft without noting them.
Maybe it's time to revise my first draft editing method!