In Clan Wars the most important is to score the most stars than your enemy to be the winner. When said about the most stars, all of your clan mates need to score three stars. If not the chances to win will be low, don't make expectation like "score at least one star is good enough". If your expectation like this you will never be a winner and never will gain the war loot because the enemy clan may score more stars than your clan. Every war need a strategy to win, let me share you some ways to score three stars in Clan Wars.
Attract and Kill The King, Queen and Clan Castle Troops
As you know a during Clan Wars you will be given a preparation day for 24 hours, during this day you will had a chance to donate and receive troops for the Clan Wars. Your enemy also had this chance, and they will filled up their Clan Castle with various of troops. Usually the stronger clan mate will do the most donation because they have high levelled troops, do the same to your Clan! Other than that, for Town Hall 8 and above, usually they will have Barbarian King and Archer Queen to guard their base. What you need to do first is to attract them to the edge or corner of your base and kill them fast. If not, they will kill your troops first during the attack. You can use any troops that will attack any target, don't choose troops that will attack specific target because they will avoid the enemy's troops. Watch examples here (LINK).
Destroy all Defence
After the enemy’s Barbarian King, Archer Queen and Clan Castle Troops all died, attack the enemy’s defence. Time is very crucial, you need to attack fast before the times up. Hog is recommended to do the attack because Hog is fast and can jump over the wall. However you still can use other troops such as Giants with combination of Healing Spell and Rage Spell to back-up your giants.
After all defence is destroyed, place other troops like archer or barbarian in every corner of the enemy base. Don’t place the troops in one place or they will take times to destroyed the all buildings. The distributed troops will attack many building in one time, so, the chance to destroy all buildings in time is more higher.
**Notes – I'm currently uploading the video example, after its finish upload, and do some editing to the videos I will put it in here to share with you guys.