It depends on the situation.

95% pf the time I carry IWB, sometimes in a tuckable holster, sometimes under a cover garment from tee shirt, to vest to jacket.

In the woods when hunting, hiking etc, I am far more likely to carry using a shoulder holster as it won’t interfere with a hip belt on a pack. I will also sometimes use a shoulder holster with a vest (especially in the winter months) or a suit coat.

When I am flying in a nomex flight suit, I use an ankle holster. It’s a close fitting one piece suit with no real option for IWB carry. An ankle holster still leaves the hand gun accessible and it doesn’t interfere with seat belts and shoulder harness or a parachute harness.