Re: Is it worth it to make stuff on your free time without even playing them?
I work on my campaigns for several months, even years. I want to create as complete a campaign as possible. I research elements I want to include in the campaign, be it art or technology. If I'm building an entire world, I include some basic science so that it looks believable to the players. I tend to create campaigns that are mostly realistic, with some cinematic elements to spice up the campaign.
That being said, I've created campaign settings on the fly. In these cases, I'm loosening up and letting my creative juices go wild. I don't develop these campaigns very much, however.
I will admit to using ideas from other sources (film, rpgs, etc.) to make my work a bit easier. But I modify them to suit my campaign. Sometimes I drop them if they turn out not to be a good fit after all.