Bidding : 1H (N) - 3H (S) - 4H (N) - Pass (S)
South, with trump support and 14 points (including 2 shortage points !) jump raises Partner's opening to 3H, a Game force. Opener accordingly raises to 4H.

Opening Lead : Queen of Spades (E) = top of a solid sequence

Declarer (N) can see at least 4 potential losers in his hand. One in Spades, two in Diamonds (A Q) and one or possibly two trump losers if the hearts break 4-1 with Q and 10 in the 4-card holding (Q 10 x x).

Declarer Play
Drawing the Opponents' losing trumps only   -   Setting up winners in a long suit by ruffing
Declarer wins the opening lead with the Spade King in his own hand, and then leads two rounds of trumps winning with his Ace and King (tricks 2 and 3). Opponent's trumps break 3-2 which is good, but the Queen is still out. Declarer sees no point in drawing a third round of trumps (as it will lose to the Queen anyway).

Instead he plays his King of Clubs (trick 4) , followed by a small Club to Dummy's Ace (trick 5).
Dummy now leads a third round of Clubs (trick 6). West discards a low Diamond, Declarer ruffs and East plays the last remaining enemy Club (the Jack). At trick 7 Declarer leads a small Spade, won by Dummy's Ace.

The three remaining Clubs in Dummy's hand are now winners. Dummy keeps leading these while Declarer discards his Diamonds, until West decides to ruff with his trump Queen. After that at best the Opponents will only win a trick with the Diamond Ace, leaving Declarer with 11 tricks won in total.

Score = 5 x 30 trick pts + 300 bonus pts = 450 pts total

Bidding : 1S (E) - 3S (W) - 4S (E) - Pass (W)
West jump raises to 3 S, a Game force, showing trump support and 13 points or more. East raises to Game.

Opening Lead : Queen of Hearts (S) = Top of a solid sequence, a good attacking lead.

Declarer (E) counts 5 possible losers : at least 2 losers in Spades (3 if the trumps break badly), 1 possible loser in Diamonds (the Q) and 1 also in Clubs.
He can perhaps avoid one loser by ruffing his 4th Club in Dummy, one if the finesse against the Diamond Queen works and one if the Opponents trumps break 3-2.

Declarer Play
Card signal by the Defence   -   Ducking play to maintain control of the trump suit
Drawing Opponents' losing trumps only   -   Direct finesse against the Queen
Declarer wins the opening lead in Dummy with the Ace of Hearts (North should play his 7 of Hearts signalling to Partner he likes his lead and holds the King). Declarer leads a trump from Dummy at trick 2, playing low in both hands ("ducking") . North should play low too (!), while South wins the trick with the Queen, who then leads the Jack of Hearts (trick 3), which is ruffed by Declarer.
Declarer now leads his trump Ace (trick 4), both Opponents follow suit. This means there is only one enemy trump left, the Jack which now is the highest card.

At trick 5 Declarer leads a small Club to Dummy's King ('high card from the short side first'), then a small Club back from Dummy to Declarer's Queen (trick 6). This is followed by Declarer's Club Ace (trick 7) on which Dummy's last Heart is discarded.
At trick 8 Declarer leads his last Club which he ruffs in Dummy. North over ruffs, but this does not matter, as with the last enemy trump now removed, it gives Declarer an extra trump trick in his own hand.
North leads another Heart at trick 9, ruffed by Declarer, who then cashes his Diamond King, followed by the Diamond 9 for a direct finesse against the Queen (trick 11). The finesse fails. North leads yet another Heart, but Declarer ruffs with his last remaining trump, then cashes the Ace of Diamonds in Dummy for a total of 10 tricks.

Score = 4 x 30 trick pts + 300 bonus pts = 420 pts total

Bidding : 1H (S) - 4H (N) - Pass (S)
With 6-10 high card points, 4-card trump support and an unbalanced hand, North jump raises directly to Game. North should pass.

Opening Lead : King of Diamonds (W) = with A K x (x) lead the King, unless the AK is a doubletone (in such case lead the Ace).

Declarer (S) can see 6 possible losers : 2 Spade losers and up to 4 Club losers in his hand. The Spade losers are unavoidable, but he can ruff Club losers in Dummy.

However if Declarer draws 2 or 3 rounds of trumps first, Dummy will have only one or two trumps left to ruff. This still leaves Declarer with 4 or 5 losers.
This is an ideal hand for a cross ruff, which enables him to ruff all 4 Club losers in Dummy.

Declarer Play
Cross ruff play   -   Cashing the side suit winners first
Declarer ruffs the Diamond King opening lead with a small Heart in his own hand.
He then first cashes his sure winners in the side suites, the Ace of Spades, followed by the Ace of Clubs (tricks 2 and 3).
At trick 4 he leads a small Club ruffed in Dummy. Dummy then leads back a Diamond, ruffed by Declarer (trick 5), who again returns a small Diamond for Dummy to ruff, and so on.
In this way Declarer wins a trick with each of the available 9 trump cards, winning 9 trump tricks plus 2 outside Aces, a total of 11 tricks.

Score = 5 x 30 trick pts + 300 bonus pts = 450 pts total

Bidding : 1H (W) - 3H (E) - 4NT (W) - 5D (E) - 5NT (W) - 6D (E) - 6H (W)
East with an opening hand himself jump raises to 3H.
West, now with 20 points in his revaluated hand (3 shortage points !), bids Blackwood asking for Aces. East shows one Ace and one King, this should be enough for a small slam.

Opening Lead : Jack of Diamonds (N) = top of a solid sequence. A small trump would also be a good defensive lead. North must avoid leading away from his Spade King !

Declarer (W) can spot 2 potential losers in the Spade suit, only one if the enemy Spades break 3-3, but this happens only about 35% of the time, not a good chance.

A Dummy reversal, ruffing the three small Diamonds, is by far the the better option here. A Spade opening lead (away from North's King) would give Declarer the contract on a platter, any other opening lead by the Defence (including a small trump lead) is fine.

Declarer Play
Blackwood Convention   -   Dummy Reversal play   -   Overtaking an Honour with an Honour to transfer the lead
Ruffing with Declarer's high cards to preserve Dummy's trump entry
Declarer wins the opening lead with Dummy's Diamond Ace, and follows up with a small Diamond ruffed in his own hand with the Ace (trick 2). He then leads a small Club to Dummy's 10, who in turn leads another small Diamond for Declarer to ruff (with the King - trick 4).

At trick 5 Declarer leads his Club Queen which he overtakes in Dummy with the King. This returns the lead to Dummy who then leads his last small Diamond for Declarer to ruff high (the 8 or 9)..
At trick 7 Declarer leads a small trump, won by Dummy, who then draws all enemy trumps in two more rounds (Declarer discards a small Spade on the third round of trumps).
At trick 10 Dummy leads a small Spade to Declarer's Ace (leading the Queen for a Direct finesse has no benefit). The Opponents will win a trick with the King of Spades but the required 12 tricks are secure.

Using Declarer's high trump cards (Ace and King) for ruffing preserves the entry to Dummy via the trump suit. This is necessary for Dummy to draw the enemy trumps in the later stages.

Score = 6 x 30 trick pts + 800 bonus pts = 980 pts total