I'm 6'2", about 210 pounds. If I'm going to me mostly standing or walking, I prefer an IWB (Crossbreed Supertuck) at about 2 o'clock. If I'm going to be sitting a lot, I'll rotate it to 3 o'clock to keep the barrel from pressing into the top of my leg. My chest is significantly larger than my waist, so I have enough "blousing" in my shirt around my waist that the gun doesn't really stand out, even with a tucked-in shirt.
For long car trips, I find a shoulder holster to be the best in terms of accessibility and comfort, but of course you have to wear some kind of outer garment, even if it's just an unbuttoned, untucked button-down shirt.