I keep track of it in my Excel chart that I list the exact order I get everything. I only started keeping track of where it came from in 2017 unfortunately, I wish I had started sooner.
I started because I needed to refer to a specific card someone had given me in a post on Cardboard History, but I couldn't remember who gave it to me ..so now I keep track of them all.
I do know some of my earlier additions, but not many. I tend to remember the firsts of something and if applicable the completion cards better then the middle.
I have kept track of the date I got every card mostly since 1999, but I was not always good about it. I have long stretches where I get overwhelmed by life or frustrated or simply put it off too long and forget.
VERY slow trading due to health problems. Not transferrable so safe to trade with, just moving is painful and can't always access the cards.
Cardboard History My COMC
New Collection Website: Cardboard History Gallery (Still under construction)
Tips on how to make your scans look like the card does in hand (No more washed out, fuzzy scans!):