A few people asked me for a tutorial, but there's really very little point in providing one when there are already tonnes of good pixel art tutorials out there, for example at:
However, I can give you a few pointers. Hopefully the above thing (yes, sorry, the dimensions are fairly big) can be of some benefit to you.
Of course, it may not be interesting at all!
I may produce more of these at some point, but I'm still a learner too, so don't take my methods and madness as the only way to go about things.