How often do you check your Truck's tire pressure?

We check psi the morning we set out on our trip, doesn't vary much as we rarely have to add air unless I air down tires (for softer ride) after last trip out. Our 16" LT truck tires are capable of handling quite a bit more than what our rig weighs anyway, I just verify they are set above a certain load handling psi and try to keep them evenly aired up across each axle. Front axle psi is about 10-15 psi lower than rear in most cases when towing.