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.
Sell your unused emblems. Just watch out you don't the carpel tunnel syndrome on your right click muscle. Actually nice of them to give us anything for stuff we don't use... Now I just wish consumables were on sale....