What I did when I was making my Tusken Raider character (I'm a GM, so he'll probably never see play) was incorporating why he left (was banished from his tribe) so that he can fit into most groups, but set his Obligation (Oath, I think) and Motivation (in this case it was power to represent his primal tendencies, although I rolled it randomly) so that he still has the feel of his original allegiance. I made his career Hired Gun (he's a male Tusken Raider, so fighting is probably the only real thing he knows) and his specialization Marauder. His starting equipment included solely heavy clothing (was going to give him Adverse Environment Gear, but decided against it, seeing that the books description is tech-based, when the Sand People use their skills to survive), a Gaffi Stick, and a gas mask. His Oath Obligation, combined with his Power motivation, add up to him being a slightly unstable power-hungry melee soldier who has a constant urge to swing a gaffi stick at the most gruff looking man in the room. Not sure any of this would translate into being a Mandalorian, but it might help with homebrewing a process for being stuff like this.