Appropriate grades or age groups:
Elementary School

Estimated time to complete activity or implement technique:
15 to 30 minutes

Materials needed (if applicable):
Reading materials!

Activity set-up/instructions or description of technique:
My children have two bedtimes-"reading time" and "lights out time". The idea is, their bedtime is a certain preset time, say 8:00, but they can choose to read quietly in bed for half an hour if they want, which would postpone their lights out time for a half an hour, to 8:30. If they choose to not read, that's fine, they can just go ahead and turn their lights out at 8:00. Needless to say, both of my kids choose to take the extra half hour reading!

Other suggestions or comments:
I also use the bedtime hour to read out loud to my kids. They are in 3rd and 5th grade, but they still enjoy listening to a good book. I read books that are a bit above their current reading levels, to stretch their vocabularies and encourage them to choose harder books (after listening to me read a book, they will often try to read a different book by the same author.)