Do not try to be cute and bid with ear wiggles, eyebrow twitches, winks, or blinks unless you are willing to accept the risk of the auctioneer missing your bids and selling the lot to a more obviously bidding person. While the bidding is going on, pay attention to what you are doing. A lot can be knocked down to someone else before you can bid, if you are paying more attention to today's crossword puzzle than the progress of the auction. During sessions of the sale that have no lots of interest to you, be courteous and refrain from talking, rattling papers, snoring, humming and whistling or any other noisy pastimes which will disrupt the sale. Remember the lots which are sold to bidders on the floor cannot be reopened in this matter.
Many firms also make provisions for specific groups of lots to be purchased as a combined lot.
In such cases the lots are generally first sold on a provisional basis, with the bidding starting at one increment over the totaled prices of the individual lots. Such combination sales must be requested in advance, and it is best to speak to the auctioneer about them at the beginning of the session, rather than just before the first lot of the proposed combination is offered. Mail bidders may also request a combination of lots, and it is not unusual for combined mail bid to take lots after the individual lots were provisionally sold to floor bidders. As a general rule, auction houses give the first bid received at a certain increment precedence over later bids at the same level. This situation is evident only when the bidding progresses in such a manner that the last bid from the book happens to be one increment below the top book bid, leaving the floor bidder with an identical bid which was received prior to the sale.