Create strong random passwords or easy-to-type passphrases, generated in your browser and never sent anywhere.
Passphrases are random words — easier to type, still very strong at 5+ words.
At least 16 characters for important accounts.
Put it straight into your password manager.
Here, yes: it’s made in your browser with crypto.getRandomValues, nothing is sent or stored, and it works offline. Even so, use your password manager’s generator where you can.
16 or more random characters, or a passphrase of 5+ random words. Length matters more than symbols.
How many guesses it would take, as a power of 2. Above 80 bits is out of reach for any attacker today.