Starting at the end? If you missed part 1, check out: 10 More Clash of Clans Strategies, Tactics, and Tricks.
# 6. Remaining shield value
Update The way shields work has been changed as of the [December 2015 update](http://forum.supercell.net/showthread.php/935404-Update-10-12-Town-Hall-11?p=5984957&viewfull=1# post5984957). It's now possible to attack without completely breaking your shield - instead, attacking an enemy base just deducts time from the shield, and you can browse enemy bases for free. We wrote this prior to the update, so watch for a revision to this section soon!
Shields play a huge role in the game. Shields are great because they give you a long window of time to let your collectors build up some cash without the constant bombardment of attackers, but the longer you play the more times you'll find yourself asking "should I give up my remaining shield time and attack, or should I wait out my shield"? 
The answer comes down to how upgraded your collectors are, and how much time remains. As you can see, even with six fully upgraded collectors, you don't stand to make that much even with a full 16 hour shield. With a little luck, you can probably make the same amount of resources with a few consecutive raids. This becomes especially true when less than 8 hours remains on your shield, since that is approaching what you can acquire from one good raid.
It is also worth noting that when you compare the value of a 12 hour shield to the cost of an opponent you slams you for the resource cap maximum (mentioned in Resource Savings: storages vs. collectors) that it comes out to close to a wash. Further evidence that an exposed Town Hall is the way to go for farming.
As you can see all of the above basically holds true for Dark Elixir too, but it does depend on your comparable skill at farming Dark Elixir.
If you happen to be so lucky (or rich) to have a Town Hall Level 10 and 3 fully upgraded (Level 6) Dark Elixir Drills, then you actually produce Dark Elixir at a rate fast enough to justify waiting out a shield. Even 2 fairly upgraded Drills on a TH9 might be worth waiting for, if you have a hard time farming DE.
# 7. Overtraining
This is a pretty simple trick that most veterans know, but it is so useful I thought I would include it. The Barracks and Dark Barracks allow you to queue troops for training, up to a maximum that depends on their upgrade level. Aside from being a way to hide resources (as mentioned in Dark Elixir Bank above), this also serves as a time savings when you are away from your village. It is particularly helpful in two scenarios.
- The top of the queue: Certain units like Dragons and P.E.K.K.A.'s have quite a long train time. If you queue them, then the troop at the top of the queue will process it's wait time even if you don't have room for it. If you work this to your advantage, you can go out for a raid with a premium line up, and return to have 4 regular and 2 dark "long train time troops" available(one for each barracks). Whenever you are planning to be away for a while, be sure you queue your troops to take advantage of this top of the queue benefit.
- 3 minutes of training: Every time you raid, the battle can take up to 3 minutes (plus the 30 second inspection period). If you've queued enough troops, they can be continuously training this entire time in the background. That's more than 30 troops that will be ready and waiting when you return, more if you include Dark Elixir troops. Keeping the queue full as you raid will lower your wait time before your next raid, sometimes all the way to zero if you only used a few troops.
# 8. Dropping on Teslas
For a reason that is not perfectly obvious to me, SuperCell decided that Teslas no longer produce a "keepout" for dropping troops. This means that if walls or other buildings are not placed close enough to them, opponents can drop troops directly on top of them. It's very important to keep this in mind when you are moving Teslas or placing them for the first time. If you happen to get lucky and spot one of these at an opponents base, consider dropping some distracting troops around the perimeter before entering the belly of the beast. Concentrated fire from all four directions can quickly erase even a sizeable force, so some sacrificial lambs on the outside can go a long way.
# 9. Luring mobile defenses
When attacking an opponent, the clan castle troops and Heroes (particularly the Archer Queen) can put some serious hurt on your ravenous pillagers. What makes it worse is that you typically encounter them when you are in the middle of bombardment from multiple defensive buildings, and they draw the attention of your troops every time they attack. The solution: lure them away with a few troops. At the beginning of a battle keep dropping one troop to attract the attention of mobile troops, until you have them outside the range of defenses, then drop a horde and let them have it. Alternatively, you can speed up the process by using a lightning spell on them once they are grouped together (provided it's worth the ~20k that it will cost you). Using this approach can save you some heavy losses, and comes with the satisfaction that you've wiped out the opponent's clan castle troops and knocked his Heroes out of commission (especially cruel if you avoid giving him a shield).
# 10. Wallbreaker AI
Ever since the version 3.54 patch, Wallbreakers have behaved a little differently. You might say they behave more intelligently than before, since they no longer attack the "wall spurs" that used to be a common design on higher level bases. While they've certainly improved, there are still exploitable weaknesses in their AI. Particularly, they will target the nearest fully enclosed (or in some cases "mostly enclosed") building. Like other "any" target troops, this means you can draw them away from valuable targets by placing dummy targets nearby.
The cheapest way to do this is by enclosing a builder's hut near other valuable buildings. Walls can play a huge role in surviving a raid. At the least, this trick will cost your attacker a few thousand elixir, but the time and wall strength it saves you may be just enough to ensure a win.