I’m thinking about credit/debit cards, but I’m sure there’s more I haven’t considered.
Use monero or cash
Cash is king
If in the US, check out privacy.com. It’s a bank so expect the signup process to be as invasive as any other bank, but they allow you to create masked cards and you can fill in any name and address you want into the billing info to keep your real info away from websites. Paid version also hides transactions you make from your actual bank.
Honestly nothing.
My problem is cash is really the only way to be truly private with your finances. Nothing else besides going great lengths using Crypto or gift cards is really private as far as I understand. I personally hate using cash, it is just such a hassle to use when compared to a debit/credit card. I always worry I don’t have enough or I have too big of denominations, or I will fail at math and look like an idiot. It is annoying to carry around, if you live in a bad neighborhood it could be potentially dangerous to carry around.
I really wish there was a private mainstream finance option but I have yet to come across any.
If possible, i make online payments with Monero. For example hosting, vpn, anonaddy and a lot of giftcards.
Probably worth moving your e-commerce sites off your google, outlook etc. Proton mail would be good. I don’t use open banking. Everything is debit card.
What do you mean by open banking?
It’s here in the UK, not sure about elsewhere, but a sort of standard for exposing financial data to 3rd party providers of apps etc. I don’t know too much about it, but linking my banking to other services didn’t sit well with me.
Additionally to what people have said, I have set up several banking accounts with different banks. That way, no bank has the full picture of what I earn or how much I spend.