As well as using common sense to not open any suspicious links/run suspicious files.
A good tip would be seeing file extensions of known file types.
I have no resident antivirus program running in the background as it takes up too many resources for my computer to handle while I play games like Crysis, and SupCom (@ <0.5 FPS
I do run my weekly schedule of Disk Defragmenter, Spybot S&D, and MalwareBytes' Antimalware, and I reinstall on average, twice a year with NO backups.


