I think most dancers favor one side or the other when turning, and a lot of us seem to favor turning to the right (clockwise), including myself. It doesn't matter what leg I'm actually turning on, but if I'm going clockwise, I can turn pretty darn well. I've even managed some consistent triple pirouettes and consecutive fouettés in that direction.
I was having some major problems with the left (counter-clockwise). Doubles were sloppy at best, and there was no way I could manage a triple. We won't even talk about my fouettés on that side (ugh). I was getting frustrated, and the mental roadblock wasn't helping.
So I started going through my mental list of what I was doing on the right that I wasn't doing on the left. First major difference? For some crazy reason, my foot moving up into passe was taking its sweet time.
Adjustment #1: Hit passe more quickly.
When I do right turns, I mentally visualize my opposite side coming around to help me turn (i.e. pirouette en de hors to the right, I make sure that my left side follows and isn't being left behind).
Adjustment #2: Bring opposite side around--don't leave it hanging!
By just adjusting these two things, I've managed to clean up my lefty pirouettes pretty well over the last week--so much so, that I managed a CLEAN triple pirouette to the left last night in jazz class! Score!
Fouettés are another story...