After 9pm, if you need to go to a faraway hotel, take TAXI instead of TOWN CAR with a driver, ignoring the advice at the Info Desk. Those drivers will charge you for at least 1,5 hrs. Taxi is cheaper!
If you are a nursing mother, good luck - the designated nursing station is one of the "companion care stations" = family restroom / no chair -sit on toilet? Airport is packed -good luck finding a seat
If you need a charging/work station - don't get on the moving walkways on your way to A gates--there's a handful of seats with outlets halfway down the hallway.
Dress light and wear little metal. If you don't need a carry on, don't bring it. Universal air travel tips, but makes getting through LAS much easier. You quick access to baggage, take the tram.
If you have a long layover, I suggest not staying in C Terminal. The terminal actually vibrates which can cause headaches if you plan on reading or working on a laptop.
Be careful when throwing away your trash by security. There are containers beside the trash cans to donate travel items to the military. If you are not careful you might throw your garbage in them!