Clash-of-clans – a good attack strategy for town hall 4

Campaign levels are like puzzles, and typically require use of specific units and/or upgraded units to succeed - especially if you are seeking a 3 star result. A few general tips for success -

• Use Tier 1 troops (barbarian, archer, goblin) in hordes to attack single target defenses (cannon, archer tower, spring traps). You'll loose a few, but the horde will overcome.
• Use Tier 2 troops (giant, wall breaker, balloon) for their
  specialized abilities, particularly to crack splash damage defenses
  like the mortar, which can wipe out your hordes. When using the
  balloon, be sure to wipe out air defense first.
• Campaign levels are not timed, so once defenses are down you can wait indefinitely to win if you want to save troops.
• Queue some troop production in your Barracks before starting a fight (even though you are full). Some of these troops will already be ready and waiting as soon as you are complete.

For per level strategies, check out the level by level video guides here.

I will also add that upgraded units help a lot. As I now attack the high-end levels, it is much easier to 3 star now that I have most units upgraded to level 4 or level 5. I also make use of the Barbarian King, which I believe makes these levels much easier since he is a very good tank, and can draw a lot of fire while your hordes disassemble the defenses.

A strategy that works for me is the standard giant-healer attack. Find and take out the air defense close to you by distracting the defenses with a couple troops, use a few wall-breakers to break the wall. Then send as many giants as needed to take out the air defense. Then you can deploy the healer and the giants will destroy most of the defenses with nearly no trouble, provided no air defenses. However, problems can often arise with this strategy. The wall breakers could die, the giants could switch to a different target. In the event of this, I find a healing spell as a good way to keep the giants alive until it is safe to deploy the healer. Place it in the spot the giants will go, or in the center of them if there attacking. For clan castle troops, a few troops will do the job. Usually a lightning spell can quickly kill a mob of archers/barbarians. Even if the air defense is still there, deploy the healer as far from it as possible. YOU NEED THOSE GIANTS! Anyway, once the defenses somewhere are taken out, deploy archers or barbs to take out some stuff. If something is out of range of a defense, shoot it down. I have used this strategy for a month, and it is very effective. I have not lost one battle since I started doing this. Understand this works differently for everyone. Hope this helps.