1 Figure out the Troops
Before you even think of defeating a castle troop in Clash of Clans, you need to ensure whether the castle has troops or not. In order to figure out the troops of a particular castle, you need to put a single unit near the castle and check if its showing any troops.
2 Defeat them away from town
If you find any troops showing up, place your troops away from the buildings but near the castle or the wandering troops.
3 Some units engage instantaneously
Some units, such as Archers engage promptly with Clan Castle troops. While usually Giants will ignore them and move towards the defences.
4 Barbarians are effective
Clan Castle troops can entirely be smashed with the help of Barbarians.
5 Circle them
Once you lure your Clan Castle troops away from the defenses, place your castle troops in a circle around them. (See Why is Clash of Clans bad for you?)
6 Do not use all the troops
Always name sure that you have not used all the troops in one go.
7 Witches are good
If you have reached a level where you have got a privilege to use the witches, make sure to add them in your troops which could immensely help you in the battle.
8 Use a Lightening spell
Always ensure that you are using the lightening spell in the right direction and position which will help you kill all defense troops.
9 Drop your troops far
It is vital to dropping your troops to a place that is far off to make an effective bait for the defense troops. (See Why is the clash of clans so addictive?)