Instructing instrument students is a good way to learn the fundementals of instrument flying, but rarely does it get you a lot of hard weather experience. In my opinion the place to do that is flying freight. The trick is to find an operator that uses well equipped (radar for tstms, boots for ice,etc.) and maintained equipment. Also if they don't force you to go when it's too bad, (yes there are times even freight planes shouldn't takeoff) that's a bonus. Luckily I was fortunate enough to fly for a carrier like that. I flew in the midwest for two years and saw just about every type of weather imaginable. Before I flew freight I could count the number of approaches I did to minimums on one hand. I feel much safer as an RJ captain having had the experiences I got while flying freight. It was a lot of work and I froze/sweated my rear off most of the time, but it was a blast.