Webex is one of the popular tools used for videoconferencing in enterprises. Here are some tricks that I find useful in Webex:
Double clickanywhere on the video portion to full screen it. Do it again to come back to windowed mode.
Ctrl -to zoom in and zoom out on the window being shared by a presenter. I find this useful when the font is too small. Note that the resolution does not increase though.
Ctrl Mto toggle between mute and unmute.