@Evergreen21 - I made one for my friend last year, mostly with good stuff from my existing stash and reused an M&S calendar from the year before to present them. (She knew in advance that I was reusing the bag and boxes and stash surplus, so wasn’t expecting M&S contents).
I also added a standalone Xmas Day gift that I bought specially for DFr, so it was clear to her that the a/c was an extra.
It went down well, so I’m doing it again this year, but this time I have put everything into numbered advent envelopes from Tiger and will use a Xmas gift bag to present them. I have also bought more items especially for DFr this year, (although some things are still from my stash).
Some of the things I have bought specifically for her to put into the a/c include: Xmas coasters, a Xmas decoration, an initial keyring, a make up bag, so not just beauty stuff.
I am adding a Xmas Day present again, just like last year.
I think it depends on your friend. I know some people would dislike a home-made calendar, even if everything in it had been specially bought brand new, others would be offended by getting stash surplus in a calendar.
I know DFr well enough to have asked her straight out if this was the sort of thing she would like. I also wouldn’t give her my sort of DIY calendar without an extra present for Xmas Day.
I really enjoy doing it and have already made a start on Xmas26!