For weight loss, I've rewarded myself along the way with every 10 pounds lost. Just things I've been wanting for a while but never got around to getting. I don't know what I'm going to do when I reach my weight loss goal but I may just throw a party!
As far as hair, I don't know what I'll do since that's so far off. I'm aiming for brastap unstretched/waistlength stretched, and right now I just made it to APL stretched so we'll see.