In 3Delight, for render settings there is no need to go overboard in terms of high settings. 

Changing the shading rate to about .75, for most final renders, is enough change from the base (default) render settings.

If you are using mirrors or reflective surfaces, and have something for them to reflect, then turn up the max ray trace depth, usually, there is no need to set it higher than 4 but that is definitely scene dependent. (4 equals through the eyelashes (1), bounce off the surface of the eye (2), through the eyelashes (3), to the camera (4).)

Each layer of transparency, and each bounce off a reflective surface counts as one and you need one more to reach the camera.