A small stapler and staples; post-it notes; ziploc bags (can be used to organize pens, markers, paper clips, etc.; can also be used as trash bags and to hold pencil shavings)

I read the other suggestions and they are wonderful!

I'm a teacher and I would definitely add Post It notes to your original list. I am asking for tissues or gift cards to buy tissues this year; that's my big need. I have one box left and will have to supply them myself unless I get donations. Some of my favorite things to get, though, are: a note from the child telling me what he/she likes about my class, small chocolate candies (Hershey's miniatures are my favorite!), and class room supplies to share with kids who run out, mostly notebook paper and pencils. I also love bookstore gift cards so I can indulge my addiction to all things quilty! Oh----just an FYI----some teachers do not eat homemade goodies because they are not sure of the cleanliness of the kitchen where they were made.....

Notepads and some sticky notes. Dollar Tree has the sticky notes much more reasonably priced than the office supply stores.

Very nice higher quality pens in different colors. I liked to color code things so different colored pens or colored files is something schools just don't give teacher's. Gift cards from an office supply store or if she teaches younger kids AC Moore.

A good hand lotion and a designer clip board. some herbal teas.