If you are using a FBL gyro.. AR7200BX, iKon, etc.. There are presets that help as well.. Beginner, sport, 3d.. Start with the lowest setting(beginner) and work your way up to your liking in addition to the transmitter dual/expo. If your heli has a flybar.. Then the dual/expo is about all you've got to tame the heli. It'll be a matter of preference.. Lee's comment is spot on.. I personally have always keep my dual rates at 100%... I want full travel, but I still use expo.. Slowing the rate to which I reach full travel. Each bird is a bit different but I like between 10-20% cyclic & 5-10% for the tail.. As Lee said it helps with twitchy or over zealous inputs.