It's a nightmare.
I only started getting really heavy into it like a month ago and I've been trying to track it with a spreadsheet but it's borderline impossible. Some of these purchases/stakes have like 10 transactions involved, each one with different fees and changes to the values of the underlying in the few minutes between each swap. And most of these wallets don't make it super easy to see exactly what your buy/sell price was like exchanges do (heck even some of these exchanges make it difficult).
I've just been notating the cash amount I start with, and then the cash value of the asset I eventually end up with at the end of it all after all the swaps/gas, and hoping that's good enough.
There are tax apps like coinpanda and coinstats, has anyone used those? Do they actually track all of the different fees and trades from all these random wallets and dex apps? Or do they just work with the exchanges?