Typically have an inspection day or days before the actual auction, go to it and be prepared or have someone that knows what they are looking at.
Watch the buyer premium fees typically a percentage of total sales price. Know what type of title you will get and that it will not be incumbered. Auction company should already have title opened with a title company or ask them.
Have your top number you are willing to pay for said site and stick to it. Don't go over just because of the excitement of the auction countdown and bids going up. Auctions are crap shoots especially if there are several people interested in the property but sometimes you can do well to.
In my other business, I brought the bank that foreclosed on the plant an offer of USD $1,950,000 (cash no finance contingency) from a client of mine. Written offer with proof of funds ready to negotiation or do a deal. The bank's auction company had done an appraisal on this plant and equipment and said it was worth $3.2 million. It ended up at auction, my client purchased the entire facility for USD $1,100,000 at auction
Good luck and stick to your number that you are comfortable with