I'm determined to not end up with a few boxes of indeterminate junk this year, so I'm being pretty ruthless about what I toss and give away. Student work gets put on a table for a few days and, if it's not claimed, it gets trashed. I hate throwing away kids' work--so depressing!--but keeping every piece of paper is just not practicable. My kids keep portfolios of projects and published writing pieces that get sent home on the last day of school, but around this time, garbage bags start piling up. If I want to save a couple of especially good projects as examples for next year, I ask the kids who made them first, then have them laminated and file them with the materials for that unit.
Taking down bulletin boards can be sad, too, even if you hate making bulletin boards like I do. They do look pretty, and they look desperate when totally naked (or covered with garbage bags so the backing paper and borders can be reused next year). Every year I ditch some charts and laminate others to save for next year.
I separated into boxes all the books that I, personally, provided for my classroom library this year through my own sweat, money, or both. I'm up to 6 boxes and still counting.
Kids leave things in classrooms all the time. I have a box in my room full of hoodies, baseball caps, umbrellas, even a basketball. I ask kids to check it every day. Whatever is left on the last day of school goes to Goodwill.
Before you throw away things like samples of textbooks, catalogs, posters, etc., ask around to your colleagues. They might be looking for the thing you're about to toss. Maybe your school has a point person to collect unwanted materials, or a central location to drop off items that are no longer needed so that everyone can paw through.
What are your favorite cleanup/packup tips for the end of the year?