When playing in a trump suit, the techniques for succeeding are:
Count the losers from the perspective of your hand. In the example deal, you started with five potential losers but made two of them disappear.
Make a plan. You have three techniques for making losers disappear: ruffing in dummy, finessing, and establishing long suits after you pull trump. When you need to ruff losers in dummy, do that before you pull trump.
Draw trump if you intend to attack a long suit and thereby establish long-card winners.
When trumps are drawn, attack your longest side suit, giving up losers early to establish the suit and cash the long winners.
Use honor cards in short side suits for transportation to achieve your plan.
You are in a contract of 2 ♠. You need eight tricks. You have two losers in trumps, two in hearts, three in diamonds, and none in clubs. You have seven losers. To make your contract, you must make two of the losers disappear.
You will win the opening lead in your hand and — without delay — you will play the ♣ K from your hand, overtaking with the ace. Do you see where you are going with this? Right — you have no fast entry to dummy outside clubs, so you must seemingly “waste” a trick by playing the ace on the king. You continue with the ♣ Q and the ♣ J, pitching those losing hearts from your hand. Now, because your trumps are so good, you will lose only three diamonds and two spades. That's eight tricks for you and another success as declarer. You are getting better and better.
You are the dealer and you are vulnerable. You fan this hand and open 1 ♠ with these 17 HCP and two length points, one each for the fifth card in spades and diamonds. Your partner responds 2 ♥, showing a five-card suit, and 11+ HCP. Game looks like a certainty, so you force your partner with a 3 ♦ bid.
Your partner decides her hand is worth another bid and follows with 3 ♥. You bid again, and your partner places the final contract at 6 ♠. You smile and wait for the opening lead and give some thought to what you expect from dummy. Six hearts cards, three-card support for your spades, and … oh, well, time will tell. West leads the ♣ A and you wait for dummy.
You are going to lose the first trick to the ♣ A. You have three diamonds in your hand that are losers, but no heart losers. What about trumps? Well, you may have been a tad aggressive here, but it's not hopeless, so don't give up.
If the only solution to your problem with a hand is a particular distribution, or if one of the opponents has to have a card for you to succeed, then plan on that happening. Just believe you will succeed. Plan for success and see what happens.
You give thought to how you are going to get back and forth from the dummy to your hand. Looks like two finesses are in order — one in trumps and the other in hearts.
West wins the first trick with the ♣ A. He's pretty sure you have no more clubs, so he tries the ♥ 8 at trick two. Well, you think, should I just put in the jack? It's best not to put all your eggs in one basket, so you go up with dummy's ace, East following with the 3.
The spade finesse must work or you're history, so you try the ♠ 10 from dummy. East plays the 6. You close your eyes and play low from hand. When you look, West — bless him — has followed low.
Why was it wise to lead the ♠ 10? Since it was your intention to finesse, the ♠ 10 from dummy was equal to the ♠ Q or ♠ J in your hand. You played the 10 because you wanted to still be in dummy if the spade finesse worked (if East covers, you will win and play two more high trumps to get the kiddies off the street). Since the ♠ 10 won the trick, you lead the ♠ 7 from dummy and win in your hand with the ♠ J. Since both opponents have followed to the first two spade tricks, only ♠ K is still outstanding. Don't waste any time getting that last trump in. Go ahead and play the ace.
Now for the moment of truth. Lead the last heart from your hand and play the jack from dummy. Miraculously, it holds. There's a lot of finessing going on here. You are pleased to note, by the way, that East did follow to the second round of hearts. That means the suit split 3-2 and it's going to run as soon as you cash the king. Your three losing diamonds are going away on hearts.
The full deal:
This is not the kind of slam you should be bidding routinely. It has a very low chance of success. Still, part of the excitement of bridge is being able to land those difficult contracts that reap such huge rewards.
Using your trump cards to win tricks when a different suit is led is known as ruffing. Sometimes ruffing is referred to as “cutting.” Think about why voids are suddenly valuable in a trump contract. You can immediately take a trick with a low trump card. It is more powerful than the ace of the suit led when you are void.
When playing in a trump contract, keep your options in mind. Long suits are valuable when the opponents have no trumps remaining. The race is on in a suit contract for the opponents to try to cash their winners and win tricks in their short suits using trumps. Take caution with the trump suit. Often it is wise to draw trumps immediately. If the possibility of a crossruff presents itself, remember that it's a great way to get more mileage out of those trump cards.