Time to share my own Linux and Windows game with you folks as a mini handbook.

Common

• Use uBlock Origin medium mode on Firefox, and remote fonts disabled in Settings
• Install Resurrect Pages addon and try to rely on archived versions of webpages instead of enabling every JavaScript and inviting danger
• Only use Ungoogled Chromium as your Chrome based browser, and use it only as secondary browser. Prefer Firefox. Avoid Brave, Google Chrome, Vivaldi and anything else.

Linux

• Linux does not need an antivirus
• Use a solid distro like Ubuntu or RedHat, with the best security teams behind them
• Rely on and prefer your distribution’s repositories for installing software, or Flatpaks or Snaps
• Verify source of Appimages (similar to portable Windows EXEs) before using. Appimage.io and Apprepo.de are good sources.
• Remember to not run every Github script you run across. However, most projects carry great reputation so you can use them safely.
• Try to avoid NPM based installations. Incidents like node-ipc teach us this.
• Install GUFW (based on iptables), set to default settings (incoming deny)
• Utilise the OpenVPN client built into your Linux distribution, unless you want to experiment with WireGuard.

Windows

• I use Ameliorated AME 21H1 version instead of LTSC, LTSB, Pro or Home or other editions, as these carry lots of spyware and official Microsoft approved malware.
• Use Malwarebytes Anti-Malware Free (MBAM Free) or Emsisoft Emergency Kit (EEK). These are top tier and free on-demand AV scanners that do not suck up your CPU all the time.
• NOTE: Kaspersky is the best in class if you can handle realtime AV performance impact, and its KSN feature combined with their 0day security is unparalleled. They are also the best in the industry at being ahead of 0day and other malware and ransomware threats, and the best at generating annual global analysis reports. Symantec/Norton does such annual reports and is not as great at anything.
• Use simplewall by henrypp, a FOSS app filter based firewall that works besides Windows Firewall. Allow connections only to programs you use that need internet, like Firefox web browser or VPN client.
• Use OpenVPN official GUI client for VPN purpose.
• Prefer official software developer/company websites first. For software downloading websites, use Filepuma, FileHorse, Softpedia or MajorGeeks. Try to avoid other websites like Download.com by CNET.

General security tips

• Avoid listening to random internet and YouTube idiots and drama queens about this topic. Go to Bleeping Computer or Wilders Security Forums if you value time and yourself.
• Prefer FOSS software as much as possible, and properly verify the reputation of closed source tools you pick. Closed source software makers have no accountability and love to remain opaque against backlash or public callouts.
• Verify the source of tools you download, and in case of Windows, do not hesitate to scan your drive-by downloads using MBAM or EEK.
• If you torrent download too much games and software even in today’s age as frequently as every week, do not hesitate to get something as robust as Kaspersky’s realtime AV suite. Movie downloading does not require such AV.
• Do not download every email attachment like a thirsty human in a desert.

VPN Usage

Use guides by https://teddit.net/u/iqBuster , and https://teddit.net/r/VPNTorrents/comments/ssy8vv/guide_bind_vpn_network_interface_to_torrent/ . They are the best folks out there regarding anything called VPN. Port forwarding is essential.