some of us do 'journal' our quilts-
your idea of the wallhanging is cute- go for it!
i keep a notebook- i write notes (like a journal) i take pictures- i add swatches--i include details---who it's for- when i started/finished it- problems-joys---what ever---it is kind of fun to sometimes go back and look at quilts i made years ago and forgot about- or i can pull out a fabric from my stash and wondering what in the world i used that for---go find it-
it is a nice way to keep a record of your projects.
i also keep a batting journal-and a thread journal -- if i am shopping for either i look through my notes and make sure i purchase what i really want- instead of getting home to find i tried that same thread (or batt) 2 years ago and hated it---i can look it up and know the what, when and why's