One of the sweet deals I have noticed in working collaboratively with another writer (or even two or three in the case of Pan Historia, my writing and role play community where I have honed my skills over the years) is that I need never really suffer from writer’s block. If you’re stuck you can get together with your fellow writer and start serving a few idea balls back and forth until you get a good volley going. Some ideas won’t work, but usually, and pretty quickly when you have two creative minds at work, you’re going to get something good going.
Even if you’re not planning on writing a collaborative novel talking to a trusted friend could still help you. Present them with the situation, ask them what they might do under those circumstances. Perhaps something they suggest will surprise you. Chances are coming at something from an entirely different point of view might spark off something in your brain. Interestingly I have played this game with author friends of mine, people who write brilliant stories, and while I seldom end up using their ideas, just the fact that we batted it around gives me inspiration for something uniquely me, and that works with my characters, my plot.
In other words even disagreeing with suggestions can be fertile ground to break through a virtual barrier that is hold you back from writing. I don’t belong to any writing groups but I imagine this is why many writers join them: to get ideas going, and to have trusted sounding boards. Ultimately you make the final decisions, or if it is collaborative, the two of you will have to agree, but the process can be full of help and support, much like the Hero’s Journey. Writing need not be a lonely business.