As you progress town hall to town hall the priorities are shifted slightly. But the biggest changes in the list come between town hall 7 and town hall 8. This is because you are going into a whole new world essentially. The players get stronger and you are only able to so far down in trophies to farm.
1. SPLASH DAMAGE!!!! - When you get to town hall 8 your main and primary focus should be on getting those splash buildings maxed! When mortars reach level 6 they deal a huge amount of damage and will one shot level 5 archers and below. Level 6 wizard towers can take out large hordes of goblins quickly when they are targeting walls so they become essential in protecting resources.
2. SINGLE TARGET - The single target defenses can be a huge help in protecting mortars when the troops are inside of their red range where they cant fire upon attackers. I feel that cannons should be done first because they are cheaper and take less time. They can also pick up a little slack that comes without an archer tower. Then should be archer towers since they make a difference against dragons especially when the attacker takes out your air defense. They are second because they are much more expensive, for example level 10 cannons are 1.6 million gold but level 10 archer towers are 2.5 million gold. Archer towers take one more day but with the new update some levels of archer towers had upgrade time reduced.
3. AIR DEFENSES - Having strong air defenses becomes essential at higher levels of the game. Eventually you will begin to see mass dragon attacks. But with strong air defenses those attacks can be averted because the attacker is worried about losing the dragons too quickly.
4. CLAN CASTLE - ALWAYS!!!! keep this as centralized as possible because this helps to take out attacking troops when your have troops in there. This baby becomes very helpful when centralized. If it covers your base then the troops can be deployed and do what they do.
5. WALLS - some may disagree with my placement on priority list but i feel it to be the best. They can be upgraded at any time with an available builder. They are good to just put that extra gold into. Also strong walls are a huge deterrent for attackers.
1.LAB - This should be first because this gives the capability to make your army stronger. In my opinion Strength > Quantity. Plus this will help to win attacks and gain trophies. This includes troop upgrades as well.
2.CAMPS - These should be second because they are essential once you have upgraded your troops. They can help with winning battles since you will have more troops. This can be a drawback if you have a perfect army composition but can also help so you can add more troops to it.
3. SPELL FACTORY - Having an upgraded spell factory after upgrading spells help because you can have more spells to take out those air defenses (if using mass air), pesky mortars (if using mostly archers, or always dreaded clan castle reinforcements. Or if you have 49% then use them to take out a builders hut or barracks.
4. BARRACKS - This is last because with all level 7 or 8 barracks you can fill the queue for the maxed army camps (excluding level 8 camps). Also allows you to recruit new troops and muster a stronger army.
Hey guys and girls hope that you found this to be useful and learned something. Sorry about some of the elixer priority ones it is really late and well im just not with it today. May all your defenses and attacks be successful! CLASH ON!!!