I use a very simple MS-Excel spreadsheet and while I have a few tabs with other info, my log is merely line by line entry. I catalog EVERY round I make.
Caliber, bullet make, style, weight, powder type and charge weight, COAL, primer, brass headstamp, and I also include what kind of ammo box I put it in to.
The box of ammo itself, if is a "newish" load of me testing, trying new or recently developed loads, is marked with the same info on a post-it note.
The box of ammo, if it's simple range fodder (9mm/124gr or .45 Hardball) simply has a DATE on the box and I can search the log with the specific date if I need to know precisely what is inside those loaded rounds.
My log allows me to keep track of how many rounds I've loaded annually and I keep round counts on my guns as well, because I enjoy doing that.
Personally, I think using paper is lunacy because I would be broken without my records and I have like 5 copies of me spreadsheets right now, I'll never lose them. Searching them is a couple simple key clicks.