To help fix the lack of control of twin fins, bend your knees, widen your stance, and get as close to the water’s surface as possible while still having control/balance. Using your inside rail to enhance turns will give you a tighter pivot. Look at how low pros get during their bottom turns at the bottom of a wave, both frontside and backside. Using only the fins to turn means you’re standing too tall and the board is too parallel to the water’s surface so you’re not leaning over that rail to bury it and slice it through the water. Most beginners/adult learners(not stating that you are one) rely too much on that center fin and forget the role a rail plays for turns
caveat: I suck at sarfing and I don't know crap about the body mechanics involved and still just scratching the surface of boar design after 25 years of blissful ignorance and only riding one type of boar (HPSB thruster).
But Wax's post above makes sense to me. I see a lot of guys too upright when they turn, and it ends up looking more swively on top of the water instead of truly driving through the turns.
Also, to each their own, but man, some of you guys make surfing sound like a job with an annual performance review. I guess everyone has different goals, but to me this a hobby, a distraction from everyday life that is supposed to be fun. I've done my 10,000 hours, and I still suck:
lifelong intermediate. At this point, I ain't optimizing my performance by riding the same boar every session. Been there, done that. Now, more like finding boars that help compensate for gradually diminishing skills, reflexes, and speed.
edit: and generally crappy waves.
Maybe I look like crap surfing different boars, but I could care less. I'm having more fun the last few years surfing than I ever did before. It makes it so much more interesting to me to find different sensations on a wave. It's such a subjective sport, it blows my mind when people on here claim there's one optimal way when it comes to boar design.
It's been fun trading boars with a few guys on here recently. Interesting to see that we will each pick out different pros/cons about the same boar.