Could someone explain what are some best practices for maximum privacy?

If you were to want to use it on Amazon, what would be right steps?

Im assuming you want to create a Bitrefill account with Tor, use a protonmail account created with Tor, and mix your coins properly before you send the money (which mixer?)

The problems I see:

1) When you mix coins, you may get tainted coins
2) No matter how many steps you take to keep your privacy, it all ends up in a doxed situation (your Amazon account, which contains your full name, address, and contact info) so what's the point? Im sure Amazon keeps that data. If you ever had a financial review by a government, or in the future the government became increasingly tyrannical about cryptos and he was to force either Bitrefill or companies that accept to have their giftcards filled through Bitrefill, to disclose this information, the government would know that you have or have had Bitcoin, this is a problem.

An alternative would be to use this only for physical redeeming codes or something like that. I've heard this can be done. But again, how do we know the physical shop we go into will not ask any information when you use such codes? Which would link the usage of the code with your dox.

Could someone elaborate on this?