Here's a very interesting set of graphs that describe idle activity and how each condition can be addressed through tuning. There are 9 graphs. If you mouse over the graph it will present tuning suggestions for what are classified as
PID controls (Prop Gains, Integrator, Decel).
http://www.online-courses.vissim.us/...controlmap.htm
Thanks to Saar on ThirdGen.org for finding this little gem.