Well you really opened up the can of worms now. Ha!Ha! I don't have much time now but the best advise I can offer is to read up on Microsofts Solution Framework. I think you will find some good advice. I really don't think there is a one size fits all solution. However, there are definatley some good practices out there. Also, you may want to look at one of Wrox publications VB
Project Management by Jake Strum ISBN 1-861002-93-9 and I like the MCSD training material Desktop Applications with MS Visual Basic 6.0 for exam 70-176 ISBN 0-7356-0620-x, and MCSD in a Nutshell (exams 70-176, 70-175)ISBN 1-56592-752-4.
Hats off to you for being so consious of your programming efforts. That to me is one of the most important aspects and will take you far.
Best of luck.