Something that helps me with creative writing/rp, when I'm having a hard time? Just write any random/stupid stuff that pops into your head. Drift in and out of streams of consciousness,  prattle on incoherently,  and even spout random nonsense,  and it isn't long before my mind starts coming up with ideas I can really work with.

Even if it doesn't work 100% of the time,  it's still 100% better than staring at the screen and "waiting for inspiration".