just go out and ski and have a good time. If you are in the right place at the right time, the sponsor will find you. Trust me, you want the sponsor to find you, it makes for a better relationship in the future because they want you first.
If you have the skills, the right attitude, and the look they are going for then you will get hooked up. Go to contests and photo shoots, sneak in if you have to and throw it down. If you got skillz everything will be fine.
If you eat shit sneaking in you will prolly get tossed out. If you stomp better than everybody else you will get a break.