Every year during tax season, I regret it: why didn't I keep my transaction records cleaner back then... Now my rough method is: directly export the trade/deposit-withdraw CSV from the exchange, then on-chain, I just use one or two addresses to check in the browser, and also separately note cross-chain, airdrops, LP in and out, things that "don't look like transactions" (otherwise, end-of-year reconciliation will really crash). Also, don't be too superstitious about "just a few transactions," because once you encounter MEV, front-running, or chaotic ordering, the transaction time and the actual price received won't match, making explanations later even more troublesome. Recently, I've also seen many retail investors complain that validators/miners are taking too much, sigh.