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.
I prefer people with mobile authentication, but it doesn't matter too much. Just add me here or on steam(send an offer with what you want first if you can): https://steamcommunity.com/id/presentlyinthepast