Recently, I went through a bunch of my trading records again, and I honestly think that the easiest thing to collapse at the end of the year isn't the market, but "what was I actually doing at the time."

My current lazy approach is: every time there's an action on the chain, I just note it down casually, take a screenshot of the transfer + transaction hash and put them in the same folder, and at the end of the month, export the transaction history from the exchange—don't wait until December to scramble at the last minute.
Especially with cross-chain transactions, where you send out on one chain and come back in on another, and in the middle, there might be issues with bridges or getting stuck, missing even one record can throw everything into chaos.
The turning point is... I used to think I had a good memory, but then I encountered a situation where an oracle quote went haywire, and everyone was waiting for confirmation, so I did too.
Looking back at the bills, I realized those transactions didn't match at all, and I suddenly understood: you can be steady, but you must keep a manual record.
Anyway, I treat it like writing a diary, so I don't have to explain myself for a long time later.