For members keen on street photography you might look at Brian Lloyd Duckett's YouTube on street photography and applying 1920's Gestalt psychology in composition; some principles will be familiar but Brian does give examples that can be useful when tying to capture an image in crowded environments.
I've been on several courses with Brian including a "one to one". They were very good and he does know his stuff. He gave me some good advice on travel photography which I found spot on.
He works on the idea of projects which you will find on YouTube and worth a look.
The outcome of the "one to one" was very much a surprise. At the end of the day he turned around and told me that I was more a documentary photographer than a street photographer!
I hadn't realised it until that moment and it has proved true.
Many thanks Alfred for this interesting link. I know a bit about Gestalt theory and a fair bit about street photography but had never before linked them together in this way. I think Brian does so in a very interesting way that throws some light on what separates a mediocre street image from an outstanding one. Something I may circulate wider amongst the SPA judging community. Very thought provoking.