I really enjoy making little community assets as I go, and a month ago I decided to spend a lazy Saturday morning (which is usually my "go do something new" time) to create what's called Steam Community assets.
There's multiple different types of these: It starts with trading cards
These drop automatically from playing the game (or if you've already played, now, based on your steam playtime). Each game can drop 4 cards, one for every 45 mins of playtime. There's 7 different cards, but each player only gets 4 (and they're not all necessary different), so you might need to trade with other people to get a full set.
Once you have a full set you can use that to receive a booster pack, and create Badges.

There's also 5 steam backgrounds, which you can apply from the Profile

All in all it's a bit of silly fun. But I really enjoyed doing it; hopefully you will enjoy collecting them!
Now back to making book 2 :)