Okay, here it is.

the handshake. hairy hands not a prerequisite

So, you start with your hand in the ‘W for Wel­ling­ton’ shape. Con­nect with your part­ner fol­low­ing the Welly foot­path rule of stay­ing left (ie. your left­most fin­ger should be on the out­side of their right­most fin­ger). The join should be made up to the middle knuckle. Then (the coup-de-grace!) curl the ends of your fin­gers over. You’re now mak­ing a sym­bol­ic rep­res­ent­a­tion of the hilly Wel­ling­ton land­scape. Slide the fin­gers apart (sym­bol­ic rep­res­ent­a­tion of a cata­stroph­ic earth­quake, if you’re so inclined), and you’re done.

So cool.