This is not a comprehensive strategy, just some notes on what I've been doing so far. I'm level 2, but only spoiling level 1 cards.

If an enemy is in range, I start off the scenario by using an attack 2 top and then the bottom of Shaping the Ether (the one that deducts 1 from attack but gives you an element at the end of your turn). I know most strategies advise against the StE bottom, but until I can generate elements more consistently, I like using it. (Also, I like being more of a "support" build, taking both the heal card and turn ally invisible card.)

Towards the end of a scenario, especially when facing a boss or otherwise key enemy, I like to line up the top of Infernal Vortex if possible, along with the bottom of Ice Spikes, for one powerful megaturn -- ditching StE before attacking to get rid of the -1 attack penalty, of course. It's really satisfying after being relatively weak the rest of the scenario.

I'm sure my strategy will change as I level up... feel free to discuss any Triforce cards at any level, but put higher level cards in spoiler tags for the sake of others. I really like this character btw!