I usually tip around 20% unless I get really good service then tip what you want
I refuse point blank to tip the staff at places like starbucks - its taking the absolute piss that they expect a tip for handing over a large black coffee
Taxis are easy to get but if you wanted to save money, you used to be able to get a bus called the Deuce which went up and down the strip all day (multiple buses) and you could get a day ticket for less than $10 (may have changed). To be honest its worth getting that just to see some of the characters that use it - always funny when you catch an elvis impersonator or a burlsque girl who works on the strip all dressed up but sat on the bus. Not sure why it amuses me but it does lol
If you are going to any of the shooting ranges for something different to do, I really like battlefield vegas as they are decent. Plus they will pick you up from your hotel in a humvee which saves having to travel around
If you want to see the grand canyon, you can go by coach but it is a long fucking slog - pick up at 0600 and back around 2300 at night but you do get to go to the hoover dam as well. Its just a long day out. If you have the budget, go by helicopter. If you want something different, go to someone like Eagle Rider and rent a harley (or equivelant, whatever suits) for a day or two and take your time, enjoy the ride.
Make sure you see a couple of shows - some offer decent discounts if you are an ex vet, but always good to catch some shows as breaks up the constant gambling scene (although you will have to go into a casino to get to the
showroom)
If it's your first time going (can't remember how long you said you were going for) but after a couple of days the glitz and glamour wears off and it does become a little tedious (ive known a few people go for two weeks or more and after 5 days were ready to come home)
Set reasonable budgets for each day and don't go over them (unless going to see a decent show etc.) - nothing worse than being skint in vegas with a couple days of your trip left to go.