Question is intended for both non-crypto and crypto companies.
We open source nearly everything we do at https://github.com/hackclub, even our finances. We have deeply appreciated the generosity of the cryptocurrency community.
We have a Coinbase account where we store received crypto. In our books, we log everything in USD and I believe we record our crypto holdings as an asset. This has worked at our current size since we are a small and cash-strapped organization focusing nearly all our efforts on those we serve.
EBIT, BTCC, GBTC, BTCG, QBTC, BITC
Watch out for momentary premiums/discounts on share price though. https://bitbo.io/ for quick calculations.