Take your side-suit winners first, when considering a crossruff

With length facing shortage in two suits, together with good trumps (spot cards as well as honours), a crossruff becomes a possibility. Because such a line involves shortening both hands of trumps, you never draw the opposing trumps. Typically the last few tricks will see opponents underruff your higher trumps. Think about it: when they run out of the suit(s) you are ruffing, but cannot overruff, first they will throw away their side-suits. Then they have will have just trumps. It is precisely because the opponents will throw away their sidesuit cards as soon as they can, that you must cash your side-suit winners preparatory to the crossruff.

What happened
Winning ♦ Q lead with ♦ K, declarer’s thoughts correctly turned to a crossruff. Cashing ♥ A at Trick Two, he ruffed ♥ 3 (with ♠ 4). He then cashed ♣ A and ruffed ♣ 2. He next led ♥ 6. Can you see what East did?

East discarded his second diamond, and now the slam could not be made. Declarer saw the error of his ways and, after ruffing the heart, immediately led to ♦ A. No good. East ruffed, and his trump return, taking out two of declarer’s trumps, meant down two.

What should have happened
Declarer must cash as many sidesuit top tricks as he needs for his slam. With eight trump tricks (all made separately) plus ♥ A and ♣ A, he needs both ♦ A and ♦ K. These cards he must lead immediately, before an opponent has had a chance to discard a diamond. The indicated line is:
Win ♦ K and cash ♦ A (key play). Follow with ♣ A and ♥ A (say ♣ A first). Then ruff ♥ 3 with ♠ 4 (a necessary - small - risk), and now you have a “high crossruff”. Ruff ♣ 2 with ♠ 8, ♥ 6 with ♠ 9, ♣ 6 with ♠ 10, ♥ 7 with ♠ J, ♣ 7 with ♠ Q, ♥ 9 with ♠ K, and ♣ Q with ♠ A. 12 tricks and slam made.

Question: What would you have done on an opening trump lead?
Answer: Your trump tally has been reduced to seven. You now need an extra side-suit winner, which can only be ♣ Q. You must now risk ♣ 8 to ♣ Q at Trick Two.

If you remember one thing...
Cash as many side-suit top tricks as you need, before embarking on a crossruff.