For me - earlier start times. As usually I have to go sleep before race finish,so I join only if friday is free or there is some really very good combo. Otherwise I still join only combos I feel to be interesting.
But in general I don't really know - it's just driver's fault,as they're getting lazier (LFS iz dying 'n stuff),some are so choosey,that they don't join races without 20 drivers (funny sometimes when there are some 25 drivers like that).
And lately there were some clashes with other events (like crashmas in 26.dec or GTWS practice race today),since community is getting smaller,it also has big effect.
Well in short - there are no real suggestions from me.