Fuente: www.suncoastbridge.com.au 
There are times when you are dealt a hand with lots of trumps in both hands e.g. 5-4 or 6-4 fits and, having drawn opponents’ trumps and ruffed your losers, you still have spare trumps. It is good declarer technique not to just sit on these trumps, but to play them out to force opponents to find discards. Often they will discard badly and allow you to establish a side suit they weren’t aware of. But remember to retain one trump in case you have to lose the lead at any time. Having said that, there is another option that comes up often. Here is the classical situation:
You are South. Partner has put you into an ambitious 6, with the Q lead. You can see 11 tricks (five spades, two hearts and a heart ruff, two diamonds and a club). It seems your best chance is for split honours in clubs – finesse the 10,and if it loses finesse the J the next time. This is about a 50% chance. So you win the A, draw trumps, finesse the 10 which loses to the Q, East returns a heart to your king, you finesse the J which loses to the K. One off.
The full hand: 
There is a 100% line to make this slam. Try it. Win the A. Draw trumps in two rounds. Play K and a heart ruff, A, K, and a ruff finishing in hand. Play a small club to the 10 with East winning the Q. This is the end situation:
Poor East is stymied. If he leads a club he gives you the last two club tricks. If he leads a heart or a diamond, he allows you to ruff in dummy whilst discarding a club loser from your own hand.. Whatever he does, he presents you with your twelfth trick.
One of the ways you as declarer can make an extra trick is via the ’ruff and discard” or ‘ruff and sluff’. This occurs when you and dummy are both void in a side suit, and you can ruff the lead of that suit in one hand whilst discarding a loser from the other hand. Obviously you can’t do this for yourself, but careless opponents often give you the chance, or a good declarer may force a defender to do it for him. In this hand, why did the first line lose but the second win? Because declarer saw the need to first eliminate the two side suits from his hands so that East when on lead has no safe exit card. This technique is called ‘stripping’ the hand.
[box]So the tip for today: when you have trumps to spare in both hands, think ‘strip and end play, and perhaps ruff and discard.’[/box]
Incidentally, here is a tip for you if you find yourself in the same situation as poor East. If you are forced to give declarer either a free finesse or a ruff and discard, opt for the ruff and discard. It will give declarer an extra trick, but perhaps not enough. For example, in our hand above, supposing the club suit was a little different: 
You win the Q Returning a club now will give declarer the last three tricks. Playing a or a will give allow declarer to discard one from hand and ruff in dummy, but he still has a club loser which he can’t get rid of.