DO NOT drop your dragons until the balloons have taken care of the air defence else you might be in deep trouble. Also, if an air defence is located in a place where your balloons cannot reach, use your lightning spells.
(No execution intro)
Drop balloons around the air defences to destroy them (at least 8 balloons per air defence)
Drop dragons after air defence is destroyed.
Drop your rage spells on the dragons / balloons
[Optional] Drop barbarian king and/or archer queen when the defences are destroyed to speed up the process.
The goal of this is to keep the dragons alive and the balloons as a distraction, if some of the balloons manage to destroy the air defences and still be alive, it is great as they can go ahead and destroy the archer towers and wizard towers and show hidden Telsas to protect your dragons. Remember to watch out for air mines which can destroy a load of balloons if clumped together.
This usually ends up getting 3 stars UNLESS they have great air defence or you run out of time. Sometimes, after your balloons die, there is still an archer tower or air defence kept alive which is bad as they may damage your dragons and cause you to only get 1-2 stars. Good luck with this strategy!