I don't care for having to much stuff hanging off my person in the field.
I carry a small fanny pack like dd with some Bullfrog bug spray/sunscreen combo lotion and my big knife, fire starter/ LED flashlight and some other "ditch type items". I carry it either with the pack in the front or clipped around sternum strap if I'm carrying a big pack. I've fallen plenty of times but rarely face first, and when I did, I could use my hands/arms to soften the fall.

I modified my bear spray holster from a belt type, to a clip on one.
I clip it to the sternum strap/shoulder strap of my pack, and then just hand carry it on return trip for second load.

I carry a very small personal knife either around my neck, or clipped into side cargo pockets of my pants.

The reason I don't like things hanging off my person is because I've seen people take falls and really bruise themselves up landing on gear they had on. Wearing a pack, most experienced people know to "turtle" if they can, but sometimes they end up on their sides with all that extra weight bearing on them. Anything that's protruding off your pack/waist belt will be putting a hurt on you if you land wrong.

Years ago a backpacking buddy was fond of wearing a metal GI type water canteen around camp or for day hikes. He fell on it one year and bruised his hip bone so bad that we had to abort the trip and carry his gear out while he limped along :'(

More than one hunter/ camper has fallen awkwardly while wearing a sheath type knife in leather/nylon holster and found themselves on the business end of it :o
Kydex holsters might bruise you, but generally speaking they won't cut thru as easy if you find yourself taking that odd fall.
  Just something to take in consideration when planning your gear selections/carry methods ;)