Excellent suggestions have been made by lots of folks already. I certainly took away some gold nuggets and will add my two cents to the pot.
Though a newcomer to the roleplaying scene, I view it similarly to writing a short story, novella, novel, whatever other medium of writing one decides to pursue. In the subject you want to write about - in terms of this site the interest check you pursue - there has to be a reason why it has intrigued you enough to invest the initial energy into joining it. Whilst it's very much reliant on the GM to create a story, setting, and a whole host of other factors, it's on the roleplayer to craft a character for the GM's world. I find it helpful when writing to find a way to emotional invest myself in the character. What would they think? What would they feel? How would they interact with the world? All these questions eventually create a story motivator, which would then place the writer in the position to discover something about the character. Namely, the writer provides the platform for the character to live. I'm not sure if I made sense, but this has kept me from burning out when writing my own stuff.
As for GMing. If I understand that portion correctly, it's akin to that of an author. Namely, before you begin writing, story boarding and world creation is paramount. Think of it like creating a stage and the props for a play. Without those things, how could you expect characters to perform to their fullest? Elicit maximum emotional impact from the audience? You can't. Not doing the necessary preparation before embarking on any writing will probably result in failure. To summarize, a GM should already have created a setting, world features, and a road map of sorts before posting an interest check. Of course, being malleable in adapting the plot to other writer's suggestions should be afforded, but you're the GM. The god of the story you're advertising. People join with the assumption that you know how to lead and direct them.
Echoing what has already been said, writing is hard. Contrary to what folks who don't write think. Waiting for inspiration or chalking no productivity up to writer's block is a myth. Think of it like exercising. To get better at running - for example - you have to continually push yourself even if you want to stop at the side and deal with your body's whining. Writing is similar. Keep prodding along, and it'll get easier. Writing is a muscle. The more you work at it, the more concentration and endurance you'll get.
I hope this was helpful. I would hate for the above to sound elitist and pompous. I assure you that's not what I was going for. Anyway, I may have resurrected an old thread. Sorry!
