The mesh smoothing preference allows you to change the smoothing angle of all mesh objects in the drawing. To turn mesh object smoothing on, go to File > Document Settings > Document Preferences and click on the Display tab.

The default mesh smoothing angle is set to 70, however you can use any angle value from 0-180. The higher the number, the more smooth, or round, the objects become. The lower the angle, the objects will appear more rigid.

There's a fine line between too smooth and too rigid. Try a few different settings to see what works best for you.