Service your computer once in awhile. By this I mean, scan your computer for viruses and malware periodically and blow the dust out of your computer with an air compressor or canned air. Ground yourself before you touch anything inside your computer. Hold the blades of your fans before you blow the dust out of them. Avoid blowing directly into your computer's power supply.

If you're comfortable altering system files lookup how to find your operating system's hosts file and alter it to block some of the most common ads. Combine this with an ad blocker to save you from yourself online.

In whatever e-mail service you use add addresses you trust to your address book. Some services offer some kind of mark (like a star) to highlight addresses you trust. Use this to help avoid scams. Never open shortened links in e-mails or any links that are not directly from trusted e-mails. Most popular sites use hyper text transfer protocol secure "HTTPS" rather than "HTTP". If it's using the secure option and it's a domain you recognize you'll probably be ok.

If you open ports on your router for hosting be sure to close/deactivate them when you're done. If you leave them open or use the DMZ option on your router you are leaving yourself open to possible scans and attacks.