Thank you for this excellent post. Really good advice about keeping detailed records, getting professional help where needed and, above all, starting the process early. It's better to assess your gains/losses well before the end of the tax year so that you can benefit by adjusting your portfolio before it is too late.
My only concern is about your comment above regarding the crypto-to-crypto trades, where you state that "They can’t tax you on this,......".
My understanding is that when you use one cryptocurrency to buy another, you are effectively selling the cryptocurrency you currently own and therefore the same capital gains tax rules will apply. And if the buying and selling is done many times, this can be simplified by pooling the trades together for each crypto.
If anyone needs to do their Tax Return for 2018-19 and requires Crypto tax reports (as an input into their UK tax return), a company which specializes in this area is TokenTax and can be reached via the following link:
https://tokentax.co/?via=jas
RE: Cryptocurency Tax in the UK - it's tax Jim, but not as we know it