Watch the Week 1: Strumming Patterns 6-11 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!
Try this exercise: choose one variation (one that you like a lot), pick a song, any song, and see when and where you can play that single variation in your back up. Next, choose another song and again include that same variation in your playing. Do this over and over and eventually that single variation becomes second nature and it will stay with you forever!
No, you are not done already. After that, choose another variation and start the process over....you see there is no end to it!