For several years, after college, I was on a regime of "one book" at a time. In those days, it was mostly classical literature or a book on film/writing craft.
I was in the habit of reading before bed, or occasionally, in the afternoon when I had some free time, over coffee.
I'd often wonder how we collectively (students) went through several books at the same time in college, and the answer now, so obvious, was because of necessity.
Jump to about two years ago, when I had a sudden revelation that my reading frequency had dipped to an all time low, and was consumed with a year of MOBY DICK (the year before, WAR AND PEACE). One book, a whole year.
At this time, I came to a reading breakpoint (yes, this is not so dramatic). Rather I can wallow in the dead poetics society, or, get the fuck out of this habit, and open the mind to new ideas.
I picked up a non-fiction business book. Something I had never done in my life. Why? I was pulled in that direction but that's another story.
But since then, I upped my reading to an average of around 40-50 books per year in the last few. I understand that this is below some overachievers, but the mean of the average American Adult's book count, according to this 2013 PEW study is 12. With a median at a paltry 5 (still more than my MOBY DICK year).
So, what's my method? It's all in a system based on formats, and multiple books at the same time.
For short non-fiction, I use ebooks. For things on the more motivational front, audiobooks is my preferred format. For tougher, more esoteric material, a good ol fashion analog book. For longer non-fiction, or any books on craft or technique or where you need to write information down, analog. For fiction, again, analog mostly, unless it's the size of a novella or shorter, and then it would be read in the ebook format.
So, I read a hardcover in the AM, listen to an audiobook in the car and on a jog. On an afternoon break, or at night, I'm on the Ipad with an ebook. I average about 3 books simultaneously, and can push to a max of 4.
Personally for me, at this moment, I could not read 3 books at the same time in the same format. This switch in format is both contextual, and tacit, and lets my brain welcome new content throughout the day.
One last thing: I love owning books. While I've come to love ebooks and find them superior on many levels especially for it's ease in annotation, I find myself having to buy the analog version as well if I really enjoyed the work, just to make this situation feel real. This is a problem financially.