I usually know what I’m going to watch next when I’m halfway through the current drama I’m watching . So for example- I watched Moon Embraing the Sun and half way through I knew I needed to watch something entirely modern and newish so I picked What’s Wrong With Secretary Kim which is its complete opposite. Sometimes there will be elements in a drama that piqued my interest and that usually dictates my future mood .There would be elements I would like to further explore as an entirety like say , mystery . Then boom - I’m watching a mystery drama that appeals to me .
I also find the “priority” section in the “my watch list “ very helpful . I usually pick what grabs me there if I don’t know what to watch .