First and most important - if it is going to be a large auction and you are carrying cash, never, ever go alone. Two is the minimum, three is better. In a crowd, you need help to watch your back, your wallet, your purchases and keep track of the lots coming up. Sometimes at a large auction, they will be selling in two different areas.
Accept the fact all auctions are rigged to some degree. It has been going on for thousands of years, since the first camel was sold in the town marketplace. The most savvy and experienced bidder is still only a semi-pro competing against professionals who do it every week for years.
Yes, there is always shill bidding. The only defense is have a max limit and never exceed it.
No, there is no reliable way to know how to psyche-out other bidders. Some have very low max and will drop out early if challenged. Some have bottomless pockets and don't care what you do or don't do - they're going to own that item.
Maybe, trust but verify. If certain items in a box or accessories on a machine/tool are critical to the deal, take a digital photo of the important pieces. I bought a lathe and when time to load it out, one of the chucks, a $500 item wasn't there. I pulled out my camera and showed the auctioneer the photo of the chuck sitting in the cabinet. I didn't pay for the lathe, but with the chuck, it was a good deal I really wanted.
Government auctions are the worst. I've seen gangs of thieves come early on the preview day disable cars/trucks/machinery so they won't start, pour oil under a transmission so it looks like a big leak, let air out of tires so the vehicle can't be moved, hide key parts of machines. The guards and auction employees were either bought off or scared off.
For a while, thieves were stealing a car, removing the wheels, doors and seats, then leaving it where it would be found. They'd then go to the salvage auction, buy it back cheap, replace the parts they had stored and re-sell it. When one friend who owns a body shop tried to bid against them, a big thug sidled up beside him and said, "That car isn't safe. Your wife or family might be harmed."
Auctions can be inexpensive fun, a source of bargains and a way to keep track of the bargains, as long as you go prepared, make your max bid list and keep your hand on your wallet.
Finally, if there were box lots of tools always keep track of who bought them and make an offer for the part of it you wanted most. Chances are, he's a dealer who is ready to take some profit right there.
thnx, jack vines