This unfortunately ruined reading for me for a long time. I associated reading with sleep, and it became a pavlovian response: a few pages in, any time of day under any circumstances, I'd start to nod off.
This is easy to fix. Just spend at least as much time reading on a treadmill or other exercise device as you do before bed and you will learn to discriminate very quickly.
I suppose that depends on the quality of the material you're reading. I like the outdoors, but unless I'm somewhere that is both beautiful and novel, a good book makes my synapses buzz a lot more.
That said I recently went for over two months without reading in the evenings - when I resumed reading (a friend literally pushed a book on me and said it needed to be read within a fortnight) I became notably calmer and less stressed.
To have colleagues note that none of the workload had changed yet I was significantly more with it was startling, and the only change I could identify was the book.
I think my strategy backfires if the book is really good. Personally my night reading is very casual, usually a light non fiction book that doesn't provoke much deep thought.
1. While I'm inside a chapter, I'll keep reading until the end of the chapter.
2. When I'm at the end of a chapter, I will stop if (and only if) I feel that I cannot invest the time to start the next chapter right now.
So short chapters are bad because I will just keep going ("oh come on, only two more pages") and long chapters are bad because I will not even start them. The sweet spot for me was two years ago when I read www.hpmor.com.
There's nothing like cracking a book open to read a few pages before bed, then noticing that all of a sudden the sun is coming in through the window and it's time to go to work...
For me it's reading things like astrophysics and cosmology. I find it peaceful to ponder that I'm a small part of a very large construct. Though I have a lot of interest in the field, the perspective really just puts my mind at ease. (Has to be dead-tree though - even a kindle has too much reminders of my work)