I've seen a lot of people complaining that the game doesn't do a proper job teaching you how to defeat DOEs. While I personally found their explanation to be enough to push you in the right direction and still allow you to experiment, I thought i'd make this topic for those who are still confused. Note that all of what is about to be said comes from my personal experience and experimentation, so if anyone thinks what I am saying is incorrect, feel free to correct me:
In order to do more than 1 HP of damage to a DOE, you must first debuff it. However, what debuff you should use will vary from DOE to DOE and thus, you should be prepared. The general rule is that every DOE is more susceptible to a certain bind or status affliction that it is compared to others. What you want to do is figure out which ones the DOE you are fighting is most susceptible to.
In terms of binds, the general rule of Etrian Odyssey applies - if it looks like it uses it a lot, you should bind it. Icy Pincer's are known for their large arm scythes, so it's best to try and use use arm binds on it. I should also note - again, this is in my experience - that only certain binds will open up the DOE to damage. I tried leg binding a certain DOE and even though it worked, I still didn't do more than 1 HP of damage. It was only when I had binded something else - I assume it was the one it was more vulnerable to - that I managed to do more damage.
In terms of status afflictions, similar rules apply. You have to find which afflictions the DOE is "weak" against. I was fighting both a Golden Deer and Furyhorn at the same time when one of my Hexers used a poison spell which poisoned the both of them and immediately allowed me to wail on them until they died. Note that even though DOEs may susceptible to multiple kinds of status afflictions, some last longer than others. Something i'm noticing a lot is that my Runemaster keeps paralyzing DOEs. I then attack with my ninja which does about 75 HP of damage, but immediately after the paralysis went away and my group continued to just do 1 HP of damage. This happened over and over again during my experimentation.
And before anyone gets confused you do NOT have to get both a bind and status affliction to start dealing heavy damage. You only have to do one or other.
It probably goes without saying, but I highly suggest having either a Gunner or Hexer around since both of them learn attacks that can bind legs, arms, and the head. I also suggest having a Blast point ready so you can use the Blast command to manually control all of your characters as well.