Honestly having maintained a distro at several different companies for a living. My advice is DON"T. As single person or small group you CAN NOT produce a distro that is better the large distros. (Unless you are creating a really really small distro.) It's a waste of your time, and reinvents the wheel.
What I do advise is:
-Figure out what it is that you really to do that is better than the existing distros
-Find a distro you like
-Make modified packages for that distro that does what you want.
-Reskin the installer, the desktop, what ever
-If you make modifications of value contribute back if possible. (Not because it's nice, but it's a pain in the ass to keep modifing things every release...)