...An odd assortment of mementos/keepsakes, rocks, old bee's nests, etc...but, the only singular items I work on as actual collections are:

Crochet patterns for hearts or things using heart motif

Crochet patterns for birds

Grab/Clip ephemeral pics -- from mags, catalogs, etc. -- of hearts and birds.

I would collect so much more -- I do love old books, and music -- but I don't seek them out deliberately, because they takes up so much space!