Also bear in mind that the less code in each method the easier it will be to pin-point the location of the error.
Also you should bear in mind that throwing an exception is a big overhead and should only be used when a real exception has occurred...something you really did not expect and cannot recover from.
http://web.archive.org/web/20100402092458/http://blog.thekid.me.uk/archive/2007/07/25/debugging-tips-for-sharepoint-and-wss-exceptions.aspx
