Always keep smile and eye contact, but must not be overly patronizing.

始终保持笑容和目光交流，但是一定不能过于做作。

youdao

However, it is far from enough for your position to keep smile always, your own opinions are of great importance.

而做到这个职位，一味地笑是远远不够的，有自己的想法很重要。

youdao

A smile costs nothing, but gives much, so always keep smiling!

微笑不需要花费什么，却能给予很多，所以永远保持微笑！

youdao

Will she keep that smile glowing long beyond the nuptial bliss?

FORBES: Prince William And Kate Middleton's Royal Wedding: The Honeymoon

Another trick for the TV camera: keep a slight smile on your face WHILE you are talking.

FORBES: Smile For The Camera -Media Training

The only way around this is to put, and keep, a slight smile on your face whenever you are in front of a TV camera.

FORBES: Smile For The Camera -Media Training