Routine Change

Hey , just started the Newbie Routine; but I have a question about changing it up (for future reference). Should I just increase the number and time of the routine or completely switch it up? Also how long before doing so? I am asking this because I know when working out I switch up the workout about every month or so just to keep my muscles guessing. I know that the penis is not muscle but I can see how changing it up may lead to faster gains. Please give me your insight.