Destroy the an Air Defence of highest level using 3 lightning spells
Use Archers/Wizards to destroy Clan Castle troops if Any,
Use Hog Riders to destroy 2nd Air defence
Unleash the balloon such that their first targets are Archer towers/Air defences/Wizard Tower
Hold some balloons for the end as some chunk of your ballons may get destroyed due to air mines or Wizard tower
(No execution notes)
This war Strategy works 9 out 10 times for attacking level 7 and 8 Town Halls. If you have more Housing space than 180 then go for an extra wizard or Hog Riders. Have Fun and remember Killer I's killing Instincts...