Public Cloud Storage provides an alternate storage for you to keep your files, it allows you to access your files no matter where you are. However, if they are not properly used or protected, your files in these storages are at risk.
Use a trustable cloud service provider.
Use the devices that you trust to connect to the cloud system.
Enable two-factor authentication which provided by the cloud service provider.
Use strong password and change it regularly.
Encrypt the files before upload it to the cloud system.
Logout the cloud system and close the browser after use.
Don’t visit suspicious hyperlink or download any suspicious files.
Don’t upload any sensitive or personal information to cloud system.