I love creating the world and interesting NPC for my rps. I like having a palate of events to toss at peoples head. But mostly I let people be spontaneous they may pick up the event I gave them or do they own thing. I enjoy including those random spontaneous bits into the bigger plan and sometimes the small things a spontaneous player did I turn into a big plot point. 

I dont plan arcs untill I saw where most the players are going, if a rp came to that point it means for me it will not die I have people interested enough to give them more of a arc story. I just love the challenge of fitting the puzzle pieces of my players into a good arc. 

As a player my self I like planning some events I want to happen to my character and so I wait for the right moment in the rp to jump into it. In oposite I plan my post before posting in a lot of cases, so that is the reason I need a day or two to post fast and sometimes longer ^^; 

Only with specific people I can go nuts and post fast and on the spot. 

So I like to think about my post before I sit down and post, as well as I like planning but I do try not to scare the spontaneous people away, by sticking to just my ideas, instead finding reason for the inconsistent they made.