Saving after I know I've probably already saved. Well, it's not a bad habit, but I get the feeling that I'm wasting time and will forever be behind by a few seconds in all my life's endeavours.
Ah, but the biggest offender would be reloading weapons when I don't need to, leaving me unnecessarily vulnerable. Maybe that's part of why I like shotguns with tubular magazines — one can stop the reload partway through and not have it be for nothing. Indeed, constantly reloading can be an integral part of using shotguns effectively as the short-range weapons they are in video games. This all reminds me of the Hunting Shotgun in Fallout: New Vegas; amazing weapon if one has the Shotgun Surgeon perk and good Agility, but the reload animation could easily glitch if one moved while reloading.