Plot-driven RP Help

First, I'm not sure if this is the correct thread to put this under, so if it isn't please let me know and I'll move it.

So, alot of people here tend to RP plot-driven scenes before, but I have never done one, as coming up with a plot is too challenging for me. Any advice as to how I can cone up wuth a good plot and keep it the main focus of the scene?

Create conflict.

Seriously, introduce side characters or events that come into conflict with the other person(s) character(s). Things will spiral off beautifully from there.