There's only one way I know how to build a tribe from scratch, and it's not guide-appropriate (not at this site, anyway)...

Want to have the acclaim of building a successful Tribe in the upcoming Gods and Heroes? Find out how with Darkgolem's new guide on how to do so, Tribes of Rome!

Your new tribe members will follow the lead of this core. If
they make jokes, then jokers will stay and make similar jokes, while
those who don't fool around will leave your tribe, or be uncomfortable.

Learn lots of tribe-related secrets at Ten Ton Hammer's G&H site.