My nightstand is small, meaning that I have to keep it really streamlined. I do most of my reading and note-taking in my bed, so for me its important to keep pens, highlighters and sticky notes on hand. Since I always sleep with my hair tied back, my nightstand also has hair ties or a clip. There is nothing worse than being on the verge of sleep, only to realize that you have to get up to get a hair elastic! I also apply hand moisturizer and chapstick right before I go to sleep, so having those two things within arms reach is a must.
I like to keep a cup of water next to my bed as well. For a long time this meant that I would end up with a collection of cups on my nightstand and none in the kitchen. I finally solved that problem by purchasing a special cup meant only for my bedside. I don’t bring cups from the kitchen upstairs because I know that cup is there, and I since I only use it for water (and it’s only me using it) I feel fine about simply washing it in the bathroom sink with soap and water.
I keep a small stack of books by my bedside, but make sure that they are only the ones I am currently reading. If it’s completed or neglected, then back to the shelf it goes!