I always see people griping about being bumped back up the second they log off...
but you can use that to your advantage. Works the best when you can dump your gold on wall upgrades or buying/selling decorations (if you are already maxed out), and if you keep 1M or less elixir in storage. Basically, you want to make yourself look unattractive to 3-star. Log off when you are finished looting to start creating your hit list.
Most of the first 10 attacks or so will come from high level players dumping trophies. They will not attack you if you don't have much in the way of loot, they will just dump trophies. These are the ones you will be revenging later for their DE when you can sit safely in the 300-400 trophy range and focus on picking through the logs. Wait until their DE drills are full. Custom create your army for a particularly wealthy village. Wait for the right moment when key defenses are upgrading. Check for CC troops ahead of time. Get your lightning spells ready. Yes, lightning spells are fair game if they attacked you first. They should have been more careful about who they dropped trophies on. This is war!
Speaking of which, you should do the same. On your way down to the underworld, try to drop trophies on TH5 and below only. They only have one spell and no use for DE and can't do much damage on a revenge strike. If you are TH7 and carelessly dropping trophies on TH8's and TH9's, you are asking for trouble.
For revenge DE strikes, I completely fill up my logs with 40 new victims using 3 trips down to (and back out of) the UW. Out of those 40 attacks, usually at least 2/3 of them will be suitable to revenge for DE. Over the course of the next few days, without even going back down to the UW, I can chisel away at my logs and easily get 10K or more in DE (I'm TH7). I start from the bottom up, since any new attacks push those off the list first.
It is important to settle in the 300+ trophy range before starting your DE revenges. You will rarely get attacked there, meaning your logs stay uncompromised longer. Those who do attack you are low level players taking your TH with a hoard of L1 barbs, giving you a free shield.