So basically, you're asking for ways to gain TC in general, regardless of what you want to buy with it.
1) Sell items.
2) Sell your art.
3) Borrow TC from a good friend who hopefully won't charge interest.
4) Play in static (automated) tourneys.
5) Play in hosted tourneys.
6) Buy a booster to expand your rewards.
7) Do surveys. (If they become available again.)
PLAY THE GAME.