If you are tired and you need to be peppy, drinking a bit of straight hot sauce really works.
Keep a pen and paper beside your bedside table. Good ideas often come as you’re falling asleep, and you won’t remember them in the morning.
Really, the most important thing is eliminating self-doubt. This is basically impossible for me, but I’ve found that if I act like a boss, I can convince myself that I am a boss when I need to be one. I copy things that I’ve seen politicians and actors do; I make eye contact with people; I try to keep my shoulders back and my head high; I gesticulate wildly and sometimes take long pauses (silence can be very intimidating). I try to act like I’m powerful, onstage and off.