Multi-Stage Attacks (Read the post about funneling below before reading this!)

The key to launching the perfect attack is to break up your attack into multiple stages.

The most popular attack, the GoWiPe (Golems, Wizards, Pekkas) is a two-stage attack.  The golems and wizards are used to create the funnel: golems are dropped first to draw enemy fire, and wizards are dropped behind the golems to destroy specific buildings to create a funnel.  Once the funnel has been created, pekkas are dropped in to advance into the core and eliminate defensive buildings and the town hall.  At the game's core, this is the most basic and simple attack, and has a very high chance of netting 2 stars IF you funnel your pekkas correctly.  If the pekkas do the "walk of shame" around the base, it'll likely be a one-star attack.

Other popular attacks are modeled after the Gowipe, and involve at minimum 2 stages:

The first stage is almost always to create the funnel, and the best troops to do that are the golem and the wizard.  Why these two troops?  Because the wizard has the highest damage per housing space ratio of any troop in the game, so wizards can take down buildings fast.  But wizards are extremely fragile, so to compensate for the wizard's squishiness, golems are dropped down first to help shield the wizards from enemy fire, and golems are used because they have the highest health per housing space ratio of any troop in the game.  Just makes sense to pair the highest damage troop with the highest health troop doesn't it?

The second stage is to move your remaining troops into the core after the funnel has been established.  These troops are commonly called by the Clash community "The Kill Squad" (or KS for short).  For Gowipe, your KS is your pekkas, clan castle reinforcements, and king (and queen if you have one).  Other attack strategies simply swap out the pekkas in the kill squad for something else.  GoWiVa uses valkyries in its KS, GoWiWi uses witches in its KS.

So that's how 2-stage attacks work: golems and wizards to make the funnel, a kill squad of strong troops to dive straight into the core.  Unfortunately, 2-stage attacks usually result in only 2 stars.  The KS, if funneled correctly, will eliminate the town hall and any defensive buildings along the way to the town hall.  But usually, the remaining defenses on the opposite end of your funnel will hammer away at your remaining troops and kill your KS and any remaining golems and wizards:

The picture above shows the funnel being made, and the kill squad diving for the core to destroy the TH.  When the KS hits the core (indicated by the green star), it will start taking fire from enemy buildings on the opposite end of the base, and the KS usually doesn't have enough health left by this point to wipe out the remaining defenses firing at them.

And that's where 3-stage attacks come into play.

3-stage attacks will use either hog riders or balloons to help finish off those last, pesky defensive buildings that stand in the way of your 2-star attack becoming a 3-star attack.  The first two stages are carried out as described above, but a "cleanup crew" stage is added once the KS has entered the core.  

In the picture above, once the KS has entered the core of the base and starts taking fire, hogs are dropped off at the far end of the base to target the remaining defenses.  Once all the remaining defenses are wiped out, it's a run against the clock to destroy everything else before the timer runs out.  Hogs are best deployed AFTER the defenses start firing at your KS.  Your KS usually has a good pool of health, but your hogs are more fragile, so it's better to have the defenses distracted by your KS than to have them firing directly at your hogs.

Balloons can also be used as a third-stage troop on certain base layouts.  If the air defenses are all clustered in the core, you can drop balloons after your KS has killed the air defenses.  You can also use balloons to pick off lone cannons and mortars that are out of range of anti-air defenses.  The choice of whether to use hogs or balloons will ultimately come down to what you are more comfortable with and what the base layout favors.

Using all the information above, you can design your 3-stage attack any way you want it:

-You can make a GoVaHo (Golems, Valkyries, Hogs): golems and wizards to make the funnel, a valkyrie kill squad to dive for the core, and hogs to target the last remaining defenses.

-You can make a GoPeLoon (Golems, Pekkas, Balloons): golems and wizards to make the funnel, a pekka kill squad to dive for the core and destroy enemy air defenses, balloons to pick off the remaining defenses

-You can make a GoGobHo (Golems, Goblins, Hogs): golems and wizards to make the funnel, goblins to rush into the core to their deaths, hogs to fruitlessly try to get a single star