A while ago, I was contacted by a student for intermediate salsa private lessons. In particular, she said that she was having trouble with double turns.
In her first lesson, I watched AND FELT the nuances of her single turns. As I had guessed from our initial telephone conversation, what this student believed was her problem with double turns actually occurred with single turns as well, but she had not realized it.
The underlying issue was incorrect weight distribution, which was affecting her balance. If you are experiencing anything like this, talk to your teacher for help.