The most common password habit is also the most dangerous: picking one password, or a couple of small variations, and using it across many different accounts. It is entirely understandable - remembering a different complex password for every email, shop, supplier portal and social account is genuinely hard, and reuse makes daily life easier. But it creates a single weak point behind everything, because the security of all those accounts collapses down to the security of the one that is weakest or unluckiest.
The reason this matters so much is the way stolen passwords are actually used. When a website or service suffers a data breach, the leaked email-and-password combinations do not stay in one place; they are collected and then tried automatically against many other popular services, on the assumption - correct alarmingly often - that people reuse the same login. So a breach at a minor website you barely remember signing up to can hand attackers the exact combination that also opens your business email, and from there your other accounts, one after another. You may have done nothing wrong yourself; the leak came from somewhere else entirely, but the reused password carried the damage straight into your important accounts.
The practical fix is not to invent and memorise dozens of strong passwords through willpower, which no one can sustain, but to use a password manager. This is a secure, encrypted tool that generates a strong, unique password for every account and remembers them all for you, so you only have to recall one strong master password to unlock it. The reason people reuse passwords - that unique ones are impossible to remember - simply disappears, because remembering them is no longer your job. Reputable password managers are widely available, and setting one up is one of the highest-value security steps a small business can take in an afternoon.
Two additional habits multiply the protection. The first is turning on two-step verification for important accounts, so that even a correct password is not enough to get in without a second code, which blocks the great majority of these automated attacks outright. The second is prioritising: if adopting a password manager everywhere at once feels like too much, start with the accounts that would hurt most if lost - business email, online banking, payment tools and anything holding customer data - and give each a unique password and a second verification step. Breaking the one-password-for-everything pattern on the accounts that matter most removes the single largest avenue by which ordinary accounts are quietly taken over.