Testing Sequentially

A Q 8 6 4
K 10 8
A K 3
K 9
K 7 3 J 10 2
6 5 4 Q 7 3 2
9 10 8 7 6
Q J 8 4 3 2 6 5
9 5
A J 9
Q J 5 4 2 Contract: 6 no trump
A 10 7 Opening lead: Q of clubs

Well, let's see. We've got 5 diamonds, two clubs, 3 hearts at best, so we're going to need to take the spade hook, whether we get the heart hook right or not. So it would seem that the hand depends on that danged two-way finesse against the queen in hearts. Or does it? Declarer should run his mind over all possibilities, and indeed there is one that lets you avoid that heart finesse, to wit: Let the opening lead ride and take the spade hook. You've gotta take it sooner or later anyway. When it holds, lose a spade. You don't want to bang down the A and continue the suit, though we can see it would work here, because on 4-2 spades, you'd be beat right there. Rather we lose a spade while retaining control of the suit to test for a 3-3 break while losing only one spade. Had the suit split 4-2, we would then go to the heart finesse for a 12th winner.
Now when you regain the lead, you use a diamond to cash the A of spades and bingo. Both defenders follow and you don't hafta rely on that heart finesse. You might note that this doesn't cost you a trick. You've gotta take the spade hook whether you pick up the heart suit or not. Nor does it cost you to lose that spade. You've still got your ace, and if the spades don't split 3-3, you can still take the heart hook. You'll get the same number of tricks as you would not losing the spade, whether the finesse is successful or not.
You might also note that we're not balancing a 3-3 split against a finesse. We are testing them in sequence. That's why we take the spade hook and lose a spade. So if the suit doesn't split 3-3, we learn with the loss of only one trick and then move on to plan B: take the heart hook. We haven't disadvantaged ourselves in relation to those who move immediately to the heart hook, and when spades split 3-3, we gain, as here.