Stumbled over an article called Fifty Ways to Improve Your Visual Basic Programs on O'Reilly's VB site today. Actually has some excellent pointer for [dare I say] most VB programmers -- and is useful even if you don't program in VB. Certainly I don't agree with everything the author suggests (I think when he says Hungarian Notation he's talking more than just putting "str" in front of strings -- keep using it, as long as the rest of the name's descriptive), but here are a few "indispensible" points, imnsftistco:

Don't forget about the keyboard. Assume there is no mouse. Provide the means to do everything (if possible) from the keyboard.
Don't use global variables. (I'd amend that to "Don't use global variables without preceeding them with the keyword "Me." -R)
Use ByVal for function parameters
Be aware of how your object looks in an object browser (that one's more clever than indispensible, I think -R)
Separate the business logic from the user interface (wish I did... -R)