Spot cards can be very important if we pay attention. You hold ♠763 ♥AK96 ♦AJ3 ♣1043 and partner opens 1♣. You bid 1♥ and partner bids 1♠. So you bid 3NT. The lead is the ♠10 (possibly from 5 since your partner bid the suit; possibly just looking for a "safe" lead). Dummy comes down with: ♠AKQ5 ♥87 ♦Q876 ♣AJ7. You play the ♠A and the Jack falls on your right. Now we are sure that LHO has led from ♠109842.
Play a low diamond toward your ♦Q. Remember this card combination—do NOT play the Queen toward AJx unless you own the Ten. You are hoping for the ♦Kx on your right. The ♦Q holds the trick. Now you can lead your precious the ♠7—planning to let it ride if LHO fails to cover. LHO plays the ♠9 and you take the ♠K. Diamond to your ♦A. The ♦K does NOT fall. Play the ♠6; LHO covers with the ♠8 and now dummy's the ♠5 is a good card. You duck a diamond and find them 3-3, so you end up with four spades, two hearts; three diamonds and one club.
BIDDING OUT YOUR PATTERN
You open 1♦ with ♠AKQ2 ♥J76 ♦K10642 ♣8 and partner bids 1♥. You bid 1♠ and partner bids 2♣—Fourth Suit Forcing (to game). You rebid 2♥, showing 3-card heart support. Partner now bids 2NT. Since you are in a game force, this is a clear "Anything else to tell me, partner?" inquiry. You bid 3♦, completing your pattern. Partner bid 4♦ (Minorwood—inquiring for Key Cards in diamonds). You show two without the Queen and partner gently deposits you in 6♦ with the ♥K lead.
Dummy: ♠10 ♥A932 ♦AJ52 ♣A642. This is not the best slam in the world, but it is far from the worst. You will need 2-2 diamonds, not only to avoid losing the ♦Q, but also because you need to discard two of dummy's hearts on your high spades, and still have two trumps in dummy to ruff one heart and a spade (after you lose a heart); plus three diamonds in your hand to ruff dummy's three clubs under the ♣A. It's your lucky day because the 40% slam comes home.