I like to throw shnowballs, but only at those groups of people who think it's good to stop and sit in the middle of the run to talk while in the way of others, and especially if they're SKIERS!
Here's how to do it without the lift operator seeing you have a shnowball:
1. Get in the lift line. (Or do the follwing steps before entering the line.)
2. Make a shnowball if you're further back in the line (out of the operator's sight.)
3. Place your shnowball(s) in your binding and fold the highback down over the top to conceal it/them while you get on the lift.
4. Enjoy. (BUT DO NOT THROW AT OTHER SNOWBOARDERS!* The cool thing about this is that skiers don't have bindings like us, so they simply cannot have their shnowballs on the lift...therefore, we have gained yet ANOTHER advantage over them! We must have a feast to celebrate this victory!)
*Unless they are doing the annoying group-sit thing as mentioned above.
Or you could just do it the common way, by using the snow on your board to make shnowballs while on the lift. But by doing that you're not guaranteed to get the perfect shnowball, of course.