If you're reading this, odds are your passwords suck. No judgment—most people's passwords suck! But don't let that become an excuse for your passwords to continue to suck.
In this video, Edward Snowden gives John Oliver some great advice on generating a good password. Specifically, don't try to think up a good password so much as a good pass-phrase. Longer passwords, as well as strings of text that aren't real words, can help protect your accounts.
I mostly use LastPass for passwords these days, but there are some other tricks you can use, too:
Assign your passwords to people or objects in a room. Think of the people at your office. Or your family that you live with. Or maybe your high school chemistry class. Any time you need a password, think up a phrase that's associated with one of those people and use it. Then when you need to remember that password, mentally go into that room to recall who's associated with what (e.g. Tim starts with T; T = Twitter).
Use your imaginary friends. I find this particularly helpful when I'm asked to create security questions. A lot of sites will force you to use pre-built security questions like "What's your mother's maiden name?" or "What's your birthday?" But those can actually be pretty easy questions to hack. For the sites that let you create your own security questions, type in things that only you would know.
Use a recurring format for special characters. Adding in symbols ($%^&*@!) is a good way to beef up your password security. But you can also confuse the hell out of yourself by forgetting what symbols went where in a password (like $e@ttl3Mar1ner$). Instead, set up a format you'll remember, like first word random characters, underscore, second word regular letters: