7.Fashion-Gotta Look Good Doing it:
Its not Critical while your leveling, but making your BO uniform is fun! Givings a little more personality, to your Crew, and lets your play with the Hundreds of awesome costume combinations avaliable. If your stumped for ideas hit up Blackavaar's Guide to Canon Colors

Yes I know this is the moral equivalent of playing dress up, and it dosen't seem very MACOy but just remember Marine uniforms are custom made to Look Sharpe! Its no accident they look that good, so you can do the same!