1 When able, feign inability.
A Protoss player is using Reaver/Corsair tactics. He sends his Corsairs to check if his Shuttle will be safe, then moves in for the attack. Zerg's Hydralisks suddenly unborrow and kill the Shuttle. The Zerg tricked the Protoss into thinking he was unable to defend, and gained both a morale victory and killed a valuable Protoss unit.
2 When deploying troops, appear not to be.
A Protoss player is making Carriers. His Carriers will be much more effective if the Terran is not expecting them, and so he places his StarGates and Fleet Beacon in a place that is unlikely to be scanned. He manages to accumulate four Carriers, and because the Terran was unaware, takes out many Tanks before Goliaths can be built to support them.
3 When near, appear far.
A Zerg burrows Lurkers just in front of his Sunkens and tells them not to attack. The Terran sets up his Tanks outside the range of the Sunkens with all of his Marines supporting them, thinking he has a solid, safe position. The Lurkers suddenly attack and the Terran army is melted because of the unexpected proximity of enemy units.
4 When far, appear near.
A Terran player plans for a very safe expansion. When his SCV finds the Zerg expanding at the Zerg natural, he builds a Bunker even though he knows that he does not plan to kill the Hatchery, and probably can't since he is so focused on economy. The Zerg, not knowing that the Terran has gone a fast expansion, pulls his Drones to take care of the false threat, thus losing mining time and defending a rush that was not ever coming. The Terran was far from being prepared to attack, but made the Zerg waste money defending by appearing nearly ready to attack.
5 Lure with bait. Strike with chaos.
A Protoss mining line looks virtually undefended and ripe for Mutalisk harass. The Zerg tries to engage it, but suddenly has his entire pack of Mutalisks Maelstromed and killed by an Archon, which were both staying out of Zerg sight in the middle of the base. The Zerg was set up to fail.
7 If the enemy is full, be prepared.
A Terran army has many tanks, vultures for backup, and is ready to move out. The Protoss begins researching Leg speed and making Zealots to prepare for his push.
8 If the enemy is strong, avoid him.
The Protoss ball is moving out in the mid-game and the Zerg has only a few groups of Lings and Hydra. The Zerg runs his forces away and begins building up his army and tech so that he can fight the enemy another time.
9 If the enemy is angry, disconcert him.
A player is upset by the power of psi storm against his Zerglings and complains that they are too strong and imbalanced. The Protoss player responds 'you dog micro come back when your mom.'
10 If the enemy is weak, stir him to pride.
The Protoss army is holed up in a defensive position in his main. The Zerg can't engage him there, and wants him to come out, so he places a very minimal amount of forces outside the Protoss base which can easily be scouted, and the rest of his army somewhere out of sight. The Protoss, thinking he is strong enough to kill the Zerg army, moves out. The Zerg brings in his hidden forces and crushes the Protoss army.
11 If the enemy is relaxed, hurry him.
The Zerg player is sitting on three bases, as happy as a little bee. Suddenly the Protoss takes the natural of a second main, threatening to have 4 bases very soon. The Zerg feels rushed and makes a sloppy decision to just attack the Protoss before this can happen, and he gets crushed.
12 If the enemy's men are harmonious, split them.
A Protoss player has his Dragoons in a nice line outside his natural, hoping an enemy will attack straight into them and his aggregate of attack will be strong in the fight. The enemy Protoss however attacks to the side of the Dragoon line, leaving several Dragoons not doing anything until ordered. His Dragoons were harmonious, but their effectiveness was split by coming in from the side.
13 Attack where he is unprepared.
A Terran player has his army in the middle of the map, ready to threaten the Protoss. Using recall, the Protoss gets a large number of forces in the Terran's main, far away from his defences.
14 Appear where you are unexpected.
A Protoss player drops three Zealots and a Dark Templar at the side of a Zerg base. He keeps the Dark Templar off to the side, and attacks with the three Zealots. Later, he used the shuttle to go to a different base. The Zerg, thinking the threat is now at his other base, hurries his units to defend it. At this time the Dark Templar in the first base moves to kill some Drones, to the Zerg's mind, as if by magic since the Zerg knows the Protoss cannot have another Shuttle yet.
15 Most spells victory, least spells defeat; none, surer defeat.
The bigger army wins. Macro is important. If you have more bases, you are ahead. If you have fewer, you are in trouble. Attack in places where your army is greater than his, retreat from places where the opposite is true.
16 One peck of enemy provisions, is worth 20 carried from home.
8 minerals stolen from the enemy base is worth 160 from your own base. Not really, but it makes some people mad (this quote would be more true if probes could eat minerals and become stronger, but sadly that feature doesn't come till StarCraft III).
Cheers! I hope this gets you thinking about the subtler aspects of StarCraft in an age where people focus a lot of their energy on macro efficiency.