In winter I wear my knife around my neck. I only do this with knives that have sheaths with a good retention (Mora's, kydex, very stiff leather).
The main reason I wear my knife like that in winter is because it prevents me from doing 'paranoid checks' every 30 seconds when I'm cruising on a snow scooter or dogsled. Feeling the knife on my chest lets me check automatically that I still have it on me. I've had a knife slip on me wearing it on a belt while doing the activities mentioned above. The knife was sheathed in a danglersheath, of which the tip got stuck somewhere and turned the whole sheath around, resulting in the loss of the knife (didn't really lose it though, it was rambling on the seat behind me).
In summer I put my knives away in the top of my pack until I arrive at camp. I tend to use a small folder during the day and only get 'the big guns' out when settled.
I've never cut myself unsheating a knife around my neck, my eyes are on the knife giving me more control while sheating and unsheating it.