Use a password manager that will enable you to remember only one password without needing to use it across all your services. Using the same password for different services can increase the harm caused if one service or the password itself is compromised.
Avoid volunteering personal information over public WIFI connections. Public WIFI allows many users to connection to the internet, and others may have access to your connection information as you browse the internet. Thus, avoid viewing or providing personal information when using public WIFI connections.
Periodically clear search history and accompanying stored data. The steps required vary by browser, but there's always some way to do a spring cleaning. Deleting stored data from websites can also free up storage space or memory on your computer and help it run faster.
Most of us these days have a WiFi box in the house and do a lot of our web surfing or movie watching over that home network. Mostly we just plug the box in to the wall outlet, connect it to our internet provider somehow, and turn it on. But is that network secure? You're probably looking at your bank accounts over that connection - could it be snooped by a guy in a van down the street with a laptop and a can of pringles?
These days the major internet companies offer you the option of using "multi-factor" or "two-factor authentication as an option you can turn on. It's a good idea. Here's how it works: to log in to a website that uses multi-factor authentication, you have to know your password, plus you also have to have some kind of extra validation step. For example, some sites will send a text mesage to the mobile phone on your account, checking to see if it's really you.