In another thread - viewtopic.php?f=15&t=43354 - fasteddy & TXSTARFIRE commented nicely on my coin record keeping. Figure I'd show some samples.
Began collecting in 1977 but the record keeping started with the Blackbook in 1980, which had a great section in the back to log purchases. The earliest actual date I recall acquiring a coin was my first 1980 penny on 1/20/80, but I didn't start recording till later that year.
As you can see from the entries, I was venturing into pre-1940 Lincoln cent territory back then, and in retrospect paying quite a bit for a 15-16 year old with a $2 weekly allowance. The 1933-D is the only remaining coin from these entries that's still in its original 2x2, some 38 years later. My source for these coins was the Woolco dept store at the mall where my Mom worked. I was mesmerized by the display case with revolving trays of coins and I hadn't yet attended my first coin show.
So I started keeping track utilizing small spiral booklets. Here's Vol 2 of my daily acquisition books, showing a key find from Feb 1985.
As my collecting tastes got more varied I began more specific lists. Here's the running entries in my wartime silver log book from 2001-2002. I'm still updating these with the newest find, but they've been quite sparse over recent years. I have a similar one for buffalos that hasn't had a new entry since 2014.
Dating my 2x2's was of course a crucial part. Early on I had a special stamp but I eventually simply wrote the date in by hand. The Japanese yen is my most recent find.