Complexity

Ensure you have a secure password by avoiding using common words, or phrases. Ensure it's easy for you to remember but hard to guess, and pick a password where it have a combination of uppercase and lwoer case letters, numbers, and symbols, try not to add these extra parts to a single word, like Cat12345!

More information can be found here

Storage

Never store your password in plain text and in plain sight. A password manager (like when your browser automatically offers up a password) is best however there are many other methods to consider.

More detail on the various methods can be found here

Sharing

Never share passwords to your more secure accounts. When you do this, you give access to that part of your life to the other person. Find another way to share some of the information you'd like to share with them. Sometimes this may involve speaking to your IT department to get permissions updated on the other users' account, or you simply showing them on your own computer.

More information on how to share passwords securely and the risks involved here