To start off you probably won't need to make free time for shredding. Unless you want to get seriously fast you could just sit in front of the tv and practise a certain pattern clean and build the speed up over time. You don't even really need to worry about certain scales, just do any pattern you can think of, and when you have that up to speed, try another pattern, until you can do just about any pattern you like. Then practise with scales. I've never spent loads of time doing nothing but shredding, and im pretty decent. Then again that's just my opinion :)

- J