My starter posts are usually 3-5 pages long in Word. I like to start earlier than the interaction point, often by a day or two, to set the scene. Even if the things that happen before the start of game aren't directly pertinent, I like to give my partner a sense of what my character and their world is like. 

I really enjoy the sort of "behind the scenes" moments in roleplay. It feels a little more realistic when my partner's characters have a life outside of the plot and their own struggles and motivations.



I do tend to write on the side of "too long", however, and it's something I really need to work on. I get caught up in the backstory and sometimes my linking into the interaction point can be really rushed or vague. The struggle is real.