Creating a campaign is hard. Creating one that holds your interest over time is harder. Creating one that interests your players and holds their collective interests is a feat of amazement. It can be done, however, with a few careful considerations and an open mind to the idea that your storyline isn’t the most important aspect of the campaign to each player.
Being a DM is hard enough without having to throwing story creation into the mix of things that must be dealt with in a game. It’s much easier to purchase a module (or download one) and follow the script. The players will probably have as much as they would if you wrote it from scratch and when things go horribly wrong (as they do) you can always blame the module author for being mean. Running an adventure you created yourself, though, is a very rewarding process for everyone if done well. Having created several campaigns of various genres, here are a few tips I’ve found out the hard way. Hopefully they’ll help you and your players live happily ever after… or die a glorious death that you’ll still be talking about in ten years.