One is lateral movement, the other is aiming. My deck's offline at the moment, so I'm going from memory... but now that I think about it, I'm pretty sure I have the right stick set to aim. Then I have the gyro set to only activate when my thumb is on the right stick. Big rapid changes in direction I use the stick and the fine adjustments don't much matter; then for fine control I hold the stick still, with thumb on top, and physically shift the deck to aim. Sometimes bracing my wrists on my knees or whatever's handy.

Then when I end up angled weird, I lift my thumb and settle back in. My play style tends to end up with me twisting around while I play anyway, this just lets me harness it a bit!