my heelsides are much sharper -- basically more of a braking maneuver. When I've forced myself to open up the heelside turn, I get that "fear of speed" feeling, so there's obviously some mental issues there.
I don't think I have the fear of speed feeling, especially on heelside. In fact when I pick up speed on a heelside carve on a blue I love that feeling. When I try to recreate this movement on a black it doesn't work this way. But now that I think of it, I do wonder if I'm accidentally braking somewhat.
This actually makes me think through the physics of this a bit. If I'm not moving fast enough in my direction of travel, then the gravity will pull the board down the fall line more and cause that back end to skid right? Maybe the reason I don't have this problem on milder grades is because that gravitational effect obviously isn't as strong on the back end of the board. That would lead me to believe that I need to weight forward more going into and throughout that first part of the turn.
The second problem is that I've not been shifting my weight back over the course of the turn. With my weight always forward, of course the back end can break free.
But then there is this. If I'm leaning too far into the turn then my edge hold breaks free and the board can wash out on me. I had an inclination that this might be the problem because I'm pretty sure I'm staying leaned toward the tip of the board with knees bend when I'm making these turns.
Of course this runs contrary to what Elit3PwnZ0r said above but it's possible that his and my problems aren't exactly the same.
This is difficult to do through words but I figured I'd give it a shot before paying for an instructor. I think I'm going to try more of a deliberate aft movement in the beginning of the turn while also trying to keep in mind my body's alignment to the board and where I'm looking as well (not downhill).