Very hard to do in practice,

Buy a laptop off Craigslist, now you have a computer completely unassociated with your name.

Use Starbucks WiFi, now you’re on a connection completely unassociated with your name.

Use tor, nobody knows where your internet traffic is coming from.

Buy Bitcoin with cash, your money is completely disconnected from you.

Communicate with some RSA based encryption. Nobody knows what you’re saying.

Filter your bitcoins through a shuffler, these are encrypted services where thousands of people send Bitcoin to the same wallet, they take a randomized fee and then output to a wallet of your choice, it’s hard to figure out which input wallet is associated with which output wallet.

Not saying impossible but in practice not feasible, there’s some academic attacks on some of these things but not much demonstrated to be practical in the real world.