When you are going to ski switch, first practice a little bit of doing this:
Turn with one ski forward more, and put a slight angle on your skis to the snow.
like this
Here, we would be turning left.
This is how your supposed to turn on skis facing forwards, but with Twin Tips, it works just as good going backwards. It's a little strange to get used to, but you'l get it
Look over your shoulder and open up your body. Ski switch more and more, it takes a long time to learn