Its probably commonly known, that you can buy snowballs for cheap off the vendor during the Winter Veil event, but with my server they constantly sell them for roughly 3g a stack after the event.
I even checked myself to make sure people were really buying them so I put 10 stacks up for 2.5g each and sold 8 of them (This was last year)
So what you do would make an alt or 2, buy them 16 slot bags (or some 14 slot bags if you're to broke at the moment) Fill the bags all up with stack after stack of snowballs. Then after winter veil. Unload stack after stack of snowballs for rougly 2-3g (see how low people are selling it at the time) and people should buy them throughout the day just for gimmicky stuff.
Just thought it would be helpful, and could help make some gold.