Updated 13 February 2017
… or at least I hope it’s a full guide, given how I’ve just finished writing about over 100 gestures etc in three articles and over 10,000 words on the topic:
British body language (on topics other than gestures such as bodily contact and proximity)
Rude gestures in the UK (divided off to make the ones above family friendly U certificate articles)
I also have a nice worksheet on the topic where students guess the meaning of British gestures, which is also on my body language and gestures worksheets page.