You can also make the plane less "jumpy" by using some exponential if your radio offers this feature. Since you can dial down your endpoints like you did I expect you can set in some expo. Expo will "soften" the response of the control near neutral but still leave full travel available. This is different than dual rates in that dual rates limit the amount of total throw whild only "softening" the neutral area slightly.

Missleman's method is good too and you can always go back as your skills develope.