Take out the highest level active( not upgrading) mortar with 2 lightning spells.
Use one barbarian to check for cc troops. If there are any, then take them to the corner and take them out with archers and barbarians only.
Deploy barbarians one the side which has mortars which are active.
Immediately deploy the archers behind them.
Do NOT use everything at once. Release them layer by layer.
When the outside buildings are destroyed, release the Barbarian King on the side with no outside buildings.
release all the wallbreakers behind the king immediately and put rage on the walls in front of the king. The wallbreakers will break to the very centre of the base.
The king will get raged and will go straight for the TH. release all the barbarians and archers behind him.
Deploy cc troops if there are any.
The base will be 2 starred and if the base is a not maxed TH7 and below, it will be 3 starred.
(No execution notes)
This has worked well for me from the time I got the King. Be sure to try it! If your king is level 5 and above you can also use his ability near the town hall to take it out more efficiently. Good Luck!