Agreeing with [@Ellri] here - often I've found that (for me) writers block stems from something going on in RL. When I'm able to deal with that - whatever the issue is - I tend to be able to write again.

Now, that isn't to say I haven't experienced massive writers block with RPs that aren't in my comfort zone. Scifi, though I do enjoy the genre, just isn't something I write well. As such, even when I push myself, I get blocked a lot while writing it.

That being said, for smaller bouts of writers block - when life is okay and its something I'm comfortable with writing - I find talking to my RP partner to be helpful. I also find listening to music that fits the mood of the post can help inspire me. And sometimes, I just need a break. I'll go read something I've read a dozen times, or watch a Disney movie or something. I find it helps to do something I enjoy, but don't particularly need to focus on. I can relax and chill out while my brain rests, and come back to the RP later with new eyes.