I have had the pleasure of facilitating many workshops and some of the favourite ones that I use to create social and cognitive presence are:
*Having participants use and adjective to describe and introduce themselves.
*Dancing to an upbeat song that sets the happy, active tone for the workshop.
*Use of Hide and Seek such as pasting action verbs on coloured paper and hiding it in various places so that participants can get to meet and greet others persons as they manoeuvre around the room.