When the auction is over, make your face-down opening lead before you write the contract on your score card. You will have time to write the contract on your score sheet as dummy places his hand on the table.
After the opening lead is made, if you are the dummy, table your cards before you write the contract on your score card. You are the dummy and will have the entire playing time of the hand to write the contract on your score sheet. Don't hold up the play of the hand.
If it is your turn to call or play, do so in a timely manner before you do anything else, such as writing down pair numbers, board numbers, or the results of the last hand.
If you are sitting North, write the results on the traveler first so that you can get started on the next hand, then catch up on your personal score sheet when time allows. As a South player, make sure to record your results accurately, since North will be busy getting the travelers scored first, and may need to consult your score sheet later.
Be aware if you will be the dealer on the next board so you can have your hand sorted and your opening call ready to get things started quickly.
If you finish a round early, use the extra time to sort your hand for the next round. A lot of players at our club would appreciate the help, and it could help a slow table get caught up.
Plan your bids and rebids so you won't have so much to think about when it is your turn to call.
If it is obvious that the opponents will be declaring the hand, plan the defense as you listen to the bidding so that you can make a quick decision about the opening lead at the conclusion of the auction. It is also okay to make your opening lead, then pick up and replace your bidding cards to the bidding box. (In some places, it is required that everyone leave their bidding cards on the table until the opening lead is made.)
Do not discuss the hands until you have finished all the boards for the round and you have extra time. You should not discuss the hands (or the other results on the board) at the table. Somebody may inadvertantly hear, and you have just helped your opponents. The director is authorized to penalize you 1/4 of the matchpoints on the board for discussing it at the table. If you need to talk about it, go somewhere where you will not be overheard after the round is over if time allows.
If you are declaring the hand or defending and you know you have the rest of the tricks, then CLAIM! Playing out several tricks when the hand is over is a waste of time. It is also unethical to force the opponents to think about the hand when you know there is nothing to think about. (Imagine what it feels like to agonize over several discards, only to find out declarer had nothing left but trumps and aces!) Claiming is the proper and ethical way to wrap up a hand when all the work is done.
We've all had really tricky situations stump us. If you have trouble deciding what to bid or what to play, think about it for a few seconds, then make a decision. Tanking for several minutes to try to awaken dead brain cells usually doesn't work and can cause ethical problems for partner due to the hesitation. Most of the time your first hunch is right. (I use a 30 second rule: if I haven't figured it out after about 30 seconds, I just take my best guess and go with it.) Of course, if you have a legitimate problem that just needs a few extra seconds to sort through or to do some counting, you have the right to think! Just be careful not to waste time fretting over a problem you can't solve at the table.
We've all been in bad contracts... I mean REALLY BAD contracts! Sweating over each and every play for several minutes as you go down 1700 isn't going to give you a better score. A couple of tricks one way or the other probably isn't going to make much difference; you earned a zero in the auction and the hand was over before the opening lead was made. Wasting time during the play of a ridiculous contract only leaves less time for the next board and makes it more likely that you will get another bad result. Take the zero, move on, and discuss the problem with partner after the game.
In a complex auction with lots of alerts, only ask for explanations as needed. I generally wait until the auction is over to receive full explanations for all the bids so that the explanations are more meaningful and easier to understand in the context of the entire auction. Unless I am considering a call, there's no need for me to ask for the meaning of every bid as they are made; this only wastes time and gives more time to the opponents to think about their bids. It could also create ethical problems if bids are not explained correctly or if one opponent is tipped off that the partnership has had a misunderstanding. (Remember that, legally and ethically, a player may not make use of any information gained from partner's explanations.) You should certainly ask at your turn to call for the meaning of any bids that may influence your decision to take action. Also, there's no need to ask about the meanings of bids that are not alerted! (If you are an inexperienced player and need help with standard conventions like Stayman and negative doubles, which are not alertable, then definitely ask if you are not sure.) If bids are not alerted, they mean what they should mean; if the bids turn out to be conventional, you cannot be harmed from the misinformation and the director will make an adjustment to compensate for the failure to alert.