Easy when you think about it

You are declarer in 7♠ on this deal:

                ♠ K Q J
                ♥ K 10 7 3 2
                ♦ A 8 7
                ♣ A J
♠ 10 9 7                      ♠ 4   
♥ J 5                         ♥ Q 9 8 4          
♦ J 9 4 2                     ♦ 10 6 5 3
♣ K Q 10 9                    ♣ 7 6 4 2
                ♠ A 8 6 5 3 2
                ♥ A 6
                ♦ K Q
                ♣ 8 5 3

West leads the ♣K and you see you have 12 top tricks. To get to 13, your best shot is to develop an extra trick in the heart suit. You can set up dummy's fifth heart, but you need North's trump for an entry, so you need spades to divide 3-1 or 2-2.

Suppose the layout is as shown above. If you aren't careful, you will promote a trump trick for West. Is there an answer?

After winning the ♣A, you cash the ♦K Q, then the ♥A. You lead a trump to dummy and play the ♦A discarding your ♥6.

Now you can afford to ruff a heart low, return to dummy with a second round of trumps, and lead another low heart, and ruff it with the ♠A, avoiding any potential overruff. Besides, this looks spectacular and style points aren't always easy to come by. Just sayin'.

Finally, you lead a trump to dummy, drawing West's last trump. You score your grand slam via six spade tricks, three hearts, three diamonds and one club.