Do you rate dramas as you're watching them or wait til the end?

I have the same habit as you, I usually like to rate them once I've watched it cause sometimes a drama can be good then the ending is bad or the other way round. So, it's better to stick it out and see how it holds up.  :) 

I usually rate after completing dramas or if I have a few more episodes left. However, in that case the rating may change after I see the ending because good/bad ending can affect it quite a bit. If the ending leaves a bad taste in my mouth it can ruin the whole drama for me, and the other way around, if I love the ending I'm willing to ignore a lot and give it a rating higher than it deserves. 

For most dramas, I do wait for when I complete it. But for those on my 'on hold', i dont usually rate them. But for the ones I dropped, i rate them below 5.

 llmsy:

I also only rate shows I've finished since my feelings usually change from start to end. I never rate anything that is on hold or dropped, since it feels unfair to slap a rating on something I have not/will never finish...

yeah i don't generally like to rate something I didn't finish. 

if I don't like it because its not my thing, i don't rate it because its just not for me and that doesn't make it objectively bad. also if the acting or plot is not well done i still don't want to give  a bad rating because there are dramas ive enjoyed in spite of a weak plot or ropey acting!

I've got 2 dropped dramas that i've rated because i watched almost all of the eps but felt like the drama romanticised problematic behaviour.  (I had a 3rd but i just changed it to unrated because it was from my early drama watching days and i just thought the plot and acting were poor)