Probably one of the worst things that a non-early riser has to do is get out of bed at the crack of dawn. I, for one, can't stand it, hence my inspiration for this material. Fortunately, there's hope for those of us who wake up feeling worse than the night before. It may not seem like it, but if you pushed yourself to sing in the shower, you might feel just that little bit better.
Start by warming up with some basic scales. That should kick-start the vocal cords first thing in the morning. The more you focus on preparing yourself for your shower singing session, the less tired you'll feel. Just get on with your routine activities as you warm up your vocal cords prior to showering.
Sing whatever's in your heart and give full vent to it; don't hold back. Try smiling in the process, for this is linked to releasing endorphins. That, coupled with singing, should make you feel very different to how you felt upon awakening.