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.
https://fate-go.us/news/?category=NEWS&article=%2Fiframe%2F2020%2F0203_user_surv%2F
A not-so-easy way to get 4 tickets, since they have a lot of questions that need answers, and some are mandatory multi-choice so you couldn't just script it up. Alas, this is your chance to speak up and give your honest opinion to the NA team, and maybe if lucky to DelightWorks?
One note is that NP skip most likely won't happen so don't bother. Interviews indicate that they consider a servant's NP an essential part of their character, and skipping that would undermine their purpose or something. While I'm somewhat ambivalent about that statement the newer NPs are really nice and fun to look at, with multiple versions showing up at random so for me at least all is well again.