A year ago I moved from a three-story house to this studio apartment (living room/bedroom, kitchen and bath). I shucked a lot of stuff.
One of the best things I did was to finally go through the photo boxes and pitch everything that was repetitive, seriously unflattering to others, uninteresting or unidentifiable - I got rid of easily 20 pounds right there. Of course I still have the negatives but I doubt that I'll keep them indefinitely. One thought that keeps recurring is that after I'm gone, very few of those pictures will be saved, so why do I need them?
Getting rid of books is harder. Over the years I've done some serious culling, but books, per se, have deep roots and keep springing back. At the moment the amount is manageable but eventually I will be donating specific items to the public library as I've done in the past. It's easier to let them go there- not only does the library get some expensive books that way but I can also reread them whenever I wish.
Books in good condition but not particularly memorable to me I donate to Friends of the Library.