Most hackers succeed not because they have some unknown method of breaking into other computers, but because they make basic mistakes that are common to most end users of computers and organizations. The most common mistakes everyone should avoid are:
update
Updates for Microsoft and Apple products are free. All you need is internet access and a little time to download and install the updates. Most users ignore the update popup and continue using their computer. Keep all your devices, apps, applications, operating systems and computers updated.
old version
Another issue similar to the above is maintaining older versions of software. Most developers only maintain the latest version of their particular application. Most users keep the old version to avoid buying the new version. Remember that outdated applications can be a vector for intrusion into your system.
download
Downloading random applications online is another threat. With so many download sites, you should make sure the program you download is from a known developer. Also, when downloading any known application, always download it from the official site. Third-party download sites often add malware and adware to downloads before they are available for download.
Copyright infringement
In a recent survey, security researchers found that almost 90% of pirated software comes with malware. Bad malware was written into the application and could not be removed. Saving a few bucks by downloading pirated applications can expose your computer to malware and ransomware.