Widen your stance on the takeoff
Set with your right arm (if you are spinning left)
Glue your chin to your shoulder
Keep your head turned...I mean really turned. Glue your chin to your shoulder and leave it there till you land. Also (although it sounds weird) make sure you set your spin with your right shoulder (assuming you are spinning left). I spin left so I go into jumps switch looking over my left shoulder. When I was learning switch spins, I had a tendency to try and lead the spin by kinda throwing my left arm back behind me and I could never get past a 3. When I started thinking about setting it by bringing my right arm across my chest and around my body, 5's came super easy.