HUGE part of shin bang is landing back seat. Seriously... so many people think that fixing your boots will solve it, which will help but nothing like not landing backseat.
If you land backseat, just fall. Fuck it, you didn't land perfectly. Many times backseat landings are caused by an improper pop in your takeoff.... I've seen it a billion times. Someone says they have shinbang so bad they want to die and you watch them ski and they're just sitting on the toilet every time they land on a jump, rail, whatever...
Its your muscles tearing away from your shins and shit... bad news.
Also, check out the shintronic, its badass for shinbang!
Check it for some good content and a view into the way skiing should be.