ok... here's just a quick one that hopefully will make sense...
I think the subject line says it all - where possible, use Functions instead of Subroutines (in LotusScript).
Over the last few years I've seen a lot of code and it seems that most people are writing their code in subroutines and not taking advantage of the return code available with a function. At the very least, one of the greatest benefits of using a function is so you can return a True/False value based on whether the function succeeds or fails.