Create strong passwords
If you use a password manager, you can let the password manager create a strong password for you. LastPass for example is a free password manager that stores encrypted passwords online.
Use a reliable VPN
A VPN is a service that allows you to browse the internet anonymously and privately by masking your real IP address and encrypting all of your internet traffic as it passes over public networks. IPVanish is an example of a VPN service.
Use a secure search engine
DuckDuckGo is a versatile search engine with privacy-friendly terms. DuckDuckGo uses encrypted connections.
Update devices and anti-virus software regularly
It is easier to break into a computer or other device if the software is not up to date.
Configure your browser so that it deletes cookies
You can let sites remember information during your browsing session, but automatically delete the cookies when you quit your browser.
Turn off location services on smartphone devices
For example on your Iphone/Ipad you can turn off location services here: Settings> Privacy> Location Services and Settings> Privacy> Location Services> System.
Use a service for safe data storage
SpiderOak for example is a solid service for safe data storage.
Use a service for encrypted and secure messaging and emails
Signal and Surespot are the safest messaging services. Tutanota and ProtonMail for safe emails
Back up your files regularly
Be aware that your files are often stored with a third party. In addition, there is a greater risk that others have access to your files. If you want to reduce that risk, you can encrypt your files.
Use a safe Browser
Mozilla Firefox is the Browser recommended for using the internet freely and privately.