What Willie said. Putting one spur higher also cocks the knee, and through this you can rest it against the trunk. Both things greatly help stabilize your positioning on skinny stems.
Another point Willie brought up, also, is elevating your lanyard. It will support more of your weight, and by it helps greatly to relieve arch pain from long hours in the spurs. Though on skinny poles an elevated lanyard is almost sure to slip if it's not held by a stub. Be most careful there. Especially when running a saw: you do not want your lanyard to slip when you're running a saw! That's bad Ju Ju!