There are loads of articles and blog posts about creating SharePoint 2007 custom workflows using Visual Studio but most of them only tell part of the story or have certain steps missing. Nick Swan has probably come closest with his post for Visual Studio 2005 but even with a post as comprehensive as this it is clear from the comments that it is something people still struggle with. Rather than rehash all of those posts I thought it would be more useful to provide an example Visual Studio 2008 solution that is already set up and ready to go.
This article does not aim to be a comprehensive guide to setting up a custom workflow. It is aimed at a .net developer audience who are already familiar with SharePoint and InfoPath development but who just need a bit of help bring all the bits of SharePoint custom workflow development together into a working solution.
This solution was created using STSDev v1.4 which gives a good starting point for a sequential workflow solution and automatically creates a .wsp file whenever the project is built. If you are not familiar with STSDev projects the .wsp can be found in the Deployment folder of the project.
Source: Aidan Garnish