What to Upgrade First

1. Wizzard towers and Mortar, Splash damage is a must because is is extremely effective at taking out barbs, archers, and goblins where as cannons and archer towers would be overpowered

2. Air Defences & Air Sweeper, 1 thing i have noticed in lower th levels is that they don't buy their air defence, or they have a lvl 1, as you get to th 4 (balloons) and especially th 7 (dragons) you will need a high level air defence to take down anything that flies in.

3. (Dark)Barracks, Army Camps, and Spell Factory. they unlock new troops and give you extra housing space... enough said.

4. Hidden Tesla's, these are great as is but there even better when there upgraded. Tesla's will 1 shot an archer of the same level so a lvl 3 Tesla will 1 shot a lvl 3 archer and a lvl 5 Tesla will 1 shot a lvl 5 archer etc.

5. Laboratory Upgrades, these upgrades make your troops and spells do more and take more damage.

6. Walls, higher lvl = more Hotpoint's = harder to break through. BUT... don't overdo it I suggest upgrading defences first and doing walls after all defences are maxed

7. X-Bows, i have nothing to say but that there the perfect weapon. 

8. Barbarian King & Archer Queen, these super humans are a must when attacking in wars and are extremely powerful when you lvl up the ability's.

9. Giant bombs, a hogs worst nightmare hide high lvl giant bombs in your base and you will wipe out them hogs like it's just another Tuesday.

10. Archer Towers, these have a large range and are great at taking down minions and stray troops.

 

Hope this helped you make wise choices with what to do with your loot. Let me know if there is soninjaing I missed out, or any questions you have on upgrades.