The Visual Studio’s SharePoint Tools team has posted about using the SharePoint Package designers in Visual Studio. The package designers allow you to manage the SharePoint package (.wsp) that Visual Studio builds. The designer abstracts many of the complexities of dealing with the SharePoint packaging xml files. The designers are a good balance between doing everything for you and giving you the ability to dump out and bypass them if you have advanced requirements. Or you could even do something in between by creating your own extensions which plug in to give you new or modified functionality.

Check out the post: http://blogs.msdn.com/vssharepointtoolsblog/archive/2009/11/02/getting-started-with-the-sharepoint-packaging-designers.aspx