All experiences in this guide come from Eternal625, he had finished farming all 250 level 10 Walls for about 2 months. That is a pretty awesome achievement!
Troops for farming:
Boost is really worth. I recommend using boost gems for farming in Clash of Clans if you are finding loot and do not need your gems too much.
In this guide, Eternal625 uses BAM for farming.
With Boost: Use 2 boosted Barracks for training Barbarians, 2 boosted Barracks for Archers and 2 unboosted Barracks for Minions. If you want to save more gems, just boost 1 Barrack for Barbarians and 1 Barrack for Archers.
Without Boost: 2 Barracks with Barbarians, 2 Barracks with Archers and 2 Barracks with Minions.
Where is the best place for farm?
There are a lot of opinions about this one, but here is the best list for you. I will create a poll to vote in the future. You are farming, so you don’t need to care about maintaining trophies. From Silver to Crystal, pushing trophy is not difficult!