I mostly do NRP so what I find that'll jump me out of a rutt is to simply go off on another story arc while enough time in the RP passes I can reboot the other one. Presumably what stumps me most is simply time, and I can only write so much about walking or driving long distances. And because suddenly jumping through a three-week voyage may not be kosher I'll drop it for the three weeks in the RP and come back to it as if there was a time jump.