I find too often new TH9s who suddenly have a need for lots of DE (that's dark elixir) due to the amount of upgrades in the lab and many many Barb King and Archer Queen upgrades.
Here is a quick guide on how to farm dark elixir efficiently.
1. Troop Composition | So you want dark elixir do you? Getting some is easier than you think. If you want to raid mostly dark elixir, using a combination of giants, a few wall breakers(no more than 15), barbs, archers, and goblins works pretty efficiently. Send in a giant to distract the surrounding towers and deploy 2 or 3 wall breakers.(depending on wall level) Sending in your barb king and archer queen(if you have one) will help as raiding with their one troops will make splash towers very dangerous. Send in some more wall breakers as you destroy the defenses in the first layer of wall with your barbs/archers and heroes. Once all the walls are clear, drop some goblins to take the rest of the dark. Ending the battle right after you have taken the dark is highly recommended since your heroes take quite a while to heal. Note that the goblins will attack the closest loot holding structure around so taking out the surrounding mines and pumps with 7-8 goblins on each collector should do the trick. You might even get a bit of gold and elixir.
2. Spells | Spells are important factors when hunting dark. There are two methods. 1 being bringing along heal and rage spells to heal and rage troops on the way to the dark storage. 2 being bringing along all lightning spells to zap the dark storage. Using lightning spells has a slightly different strategy. This strategy can be found below.
3. Zapping Dark Storages | This strategy i have found personally very effective. If you are not gemming your barracks and spell factory or simply you cannot get in more than one raid before you have something else to do, this method is simple and easy. If you have an archer queen, this strategy is particularly easy. Fill your spell factory with lightning spells and your army with either a bag, or bam composition. You will be able to get around 1500-2100 dark in two raids. I recommend farming while using this strategy and to be around 1500-1700 trophies. There are two raids involved with this process. First, find a base with either lots of dark elixir in the storage, or with a relatively easily accessible storage. If you find a base with a relatively accessible storage, you should be able to easy take it down with your bag/bam. Deploy the archer queen and the barb king later after the storage can be easily taken. Once you have the dark, quickly end. As I have mentioned before, AQ and BK make it much easier to raid for dark. Once you have finished your raid and have gotten an easy 700-1000 dark, go do another raid. This raid includes zapping dark elixir and sniping town halls. Once you find a base with around 2000+ dark in it, use your lightning spells for an easy 800+ dark. If who you are raiding is a farmer, snipe the town hall with a few archer or your AQ. You can also snipe easy town halls to keep your trophies relatively the same and not drop trophies due to this strategy(gold league has a ridiculous amount of farmers). There you have it! Using this strategy before work/school, when you're eating breakfast, or whenever you get a chance, will give you plenty of dark to increase your hero level, max your dark troops, and have your friends wondering where that lv.4 golem came from.
4. Barching | Sadly DE does come at a cost, whether it is spending all of your elixir on lightning spells or creating your army for the sole purpose of hunting dark, players seem to be turned away by the fact that they farm much less resources when using a specific army for hunting DE. There is an alternative though. Barch! Using a combination of barbs and archers, you will be able to get a significant amount of DE and be able to raid for gold and elixir as well! Not only will you be able to farm for lots of DE, but you will be able to raid for a ton of resources around the table! I find this farming strategy the most effective and efficient way to farm for resources all around. People who would rather hunt for all resources including DE should use this strategy.
Hope this helped! If you have a better way of farming dark elixir, don't hesitate to comment. Any comments are greatly appreciated. Cheers!

