All those sidewalk salts and road salts will work, but the best way to go is something as small course as possible. Like what was said, the salt melts the snow, and then it re-freezes on the cold snow underneath it. With the heavy course salts, it doesn't affect as much snow. Also, a lot of those bags of salt you buy at stores, also mix in sand and gravel. It's great for sidewalks, but terrible for ski/snowboard bases.
When I was running a terrain park, the absolute best stuff I found was from a farmers co/op type store. It was a salt powder. It was almost the consistency of flower, reacted almost immediately, covered and froze the entire surface, and lasted a long time. Unfortunately, I could never get more of that. (Thanks to working for a shitty/cheap resort).
The fertilizers also work wonders. I believe it's calcium chloride that is the main choice for more places. Obviously, it's more expensive. But it tends to last longer, works deeper in the snow, and is easy to spread.