Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
Here we can discuss about you favorite skins (do topics and say why we like the specified skins). By the way, this applies for everything, even for weapons.