Avoiding audio clipping in Sonar X2 Producer

Hi all,
 
Regarding avoiding audio clipping in Sonar X2 Producer, what's the easiest way to do this in a project containing only soft synths? Should I adjust the main volume of the tracks in question for the entire song? Or there is a method of recording volume automation at the required points to bring them down a touch? Or should I bring the master down? It's mainly the left channel that's clipping slightly.
 
Thanks!