I have quite a few dramas on hold that I don't hate...but not sure I want to continue either...

What helps you guys make the decision of finishing or dropping a drama that just isn't doing it for you?

Is it a decision you make instantly or you keep trying to watch the drama? (so long as you don't completely hate it)

I usually try to give it a few episodes (maybe 3-4) because some dramas just start slow. If I really hate it, I'll drop it earlier though, and if it was recommended to me by someone who typically has the same tastes I'll give it a little longer. When it starts to become really tedious to watch rather than entertaining, I'll always drop.
My main one is Birth of a Beauty...I'm 10 episodes in and so much has happened, but how are there still 11 episodes left...I just don't understand where the story can go from here...

It's not a terrible show, but I just don't see where the second half can go since most of the secrets are already out in the open...
I'd definitely drop at the halfway point if you aren't enjoying it. The second half should get better, not worse.
I'll watch maybe 3 episodes,and if I still ain't feeling it then I'll drop it.....Then sometimes after a couple of months if I don't have anything else to watch then I'll retry it....I did that with DOTS...I kept hearing what a beautiful love story it was,so I tried it.....I ended up dropping it both times at eisode 3...I never understood the hype for it tbh-__- Anyway the point is watching dramas should be enertaining and fun,not a chore...If you don't like it,then I would just drop it ....I'm not gonna force myself to watch someone that's boring the life outta me,when I could be watching something I really enjoy
Yeah, I get what you mean about DOTS. I definitely forced myself through it. There were aspects of it I really loved, but overall seemed kind of lacking.  **SPOILER**
The biggest thing to me with DOTS was that no one died.  How dangerous and horrible their situations were and yet everyone came out pretty much unscathed...Sounds weird that this is a negative thing for me...but it would have more realistic for one of the mains to die.
I tried forcing myself,but I just couldn't do it xD.....I feel you about the no one died .....You would think someone wouldv'e died especially since half of the drama was about war,and soldiers.....The only good thing about it was no love triangles....I still having second lead syndrome....The fact that it's easy to root for the main couples was good....I just didn't feel any chemistry between them:/
I kind of agree about the chemistry. Which I find ironic since they're getting married haha
i give the first 4 episodes a pass, but if episode 5 still doesn't grab me i drop it.

on a rare occasion i'll drop dramas before the end of the first episode if it really annoys me, or i can't see the point or i'm bored for example

Imaginary cat - depressing and annoying
bride of habaek, i was so bored i paused to mop my floor - i knew it wasn't for me
kill me, heal me, i didn't like the way they fetishised mental illness.
Normally, I would give it atleast 3-4 episodes, before I decide to drop it. But I'll drop a drama at any point, when it begins to bore me and I lose interest and don't care what happens to the main leads (like in Bride of Habaek lol)
Seriously, I'm a pro at dropping dramas. My no. of dropped dramas is more than half the number of my completed dramas :p

I usually wait for at least 50% of the whole drama to be out/released to start watching it. The 50% or 8 episodes out of 16 episodes marathon, is usually enough to give me the sense of the drama. Sense in whether i like it or not. Some dramas do drop it after only 4-6 episodes, and it usually has to do of who the writer is. So around 25% to 50% episodes of a drama...
it depends ... sometimes i'll just put it on hold because I'm just not in the mood for that genre at the time, but if I come back to it and I can't still enjoy it I drop it. Sometimes I'm just fed up with an actor bad acting or the cheeziness of the script and I drop it midway.
Anyways, if I can't enjoy it I drop it :p
same as most up, I always watch the first 5 episodes first then decide from there. That said, most often I drop the last few episodes as Kdrama tend to get draggy towards the end. 
If I really like the plot, actors or chemistry, I will persist and watch about 5 episodes even though the plot moves slowly or there's annoying side story. If I still can't take it after 5 episodes because there's not good enough reason for me to continue, then I will drop it. I have encountered drama with 70 over episodes (not a fan of long dramas), but the chemistry of the main leads was so good and the plot for their story is sweet that I managed to complete the drama with some fast forwarding of the side characters story. There's instances of 20 episodes drama where I liked the plot synopsis but the execution was not realistic and was moving too slowly so I had to drop it.