Watch the Week 1: Strumming Patterns 1-5 online guitar lesson by Roberto Dalla Vecchia from Flat Out Flatpicking
There is a time and place for these variations. They are used only to add color to the original bass/strum pattern. Do not go overboard!
Aside from helping you become a better guitar player, these patterns will also make you a better overall musician for any band that you care to join.