Read the crowd and try to label all the bidders; then respond accordingly.
I've purchased a few properties from estate auctions and it's my favorite way to buy. Each time I've used a different 'technique'.
Suggestions:
1) Have someone go with you that will hold you to your top dollar and not get emotional. I take my realtor along.
2) Know how the auction will run. In my area bidding goes for a 10 minutes or until it dries up, auctioneer takes a break and talks with the seller/estate and buyers, then opens up bidding for a bit then it's done.
3) I don't like anyone in the room knowing who I am or why I want the property. The person with the most information in the room is in the best spot. Others not knowing you helps.
4) Don't let the auctioneer hold you to $5k increments...go down to $1k or less.
My last 3 auctions:
1) I waited till the bidding stalled then bid a few times. After we came back from break I waited until the auctioneer was saying "going....going....and" then I bid again. Other bidder walked off pissed cause he was done. I was at my max and wouldn't bid again, but it was a game of chicken.
2) Bidding was starting to starting to boil down to a few bidders and I jumped the bid. They asked for $70k and I blurted out $75k (my first bid)...the room stopped, looked at me and no one else bid. I had put in an offer before the auction for $75k and they turned it down.
3) Waited till they were down to serious bidders then kept bidding as soon as it was too me. (Other bidder says 80, I immediately say yep before the auctioneer even asks me to bid...we did this for a few rounds till the other bidders get the feel I would pay anything). Year later I sold the pole barn to a neighbor who was at the auction (most people wanted the barn, not the house) and the house separately.