Just steam level? Crafting badges is basically it as far as I know.
If you wanna know the best way to get badges, you just gotta collect full trading card sets, usually the simplest way is to buy em.
Marcusd0 sells sets here on jsp, so you could prob hit lvl 3 pretty cheap:
https://forums.d2jsp.org/topic.php?t=77508941&f=279PS. If you do buy sets and craft badges, you should only need about 30 sets IIRC, and I would also wait until the winter sale starts for steam before you actually craft them, because you'll get free limited time winter sale trading cards for each badge you craft. It's just free stuff, not bad.
This post was edited by Shinigami on Dec 14 2017 02:06am