After watching Jan Urschell's Cyberpunk streets videos, I got a major itch to do something very similar. I wanted to do something more than just a copy though, so I used this as an excuse to model and texture the ultimate umbrella!
I modelled the rough form of it from reference and then subdivided it several times before applying an nCloth simulation to it. I wanted subtle, realistic creases :) After that I spent a lot of time inside Substance Painter trying to get a good material. Wet plastic just after it's rained is a tricky thing to recreate! I used many layers of procedural noise and grunge to adjust opacity and roughness. The water droplets filter in SP helped too.
There's 3000 people in this scene, each with an umbrella. MASH and Arnold standins were used to scatter them around and actually make the scene renderable.
The lighting and post processing are kind of my love letter to the looks of Tim Burton's first Batman film and David Fincher's Seven.
I try to stream at least once a week on http://twitch.tv/liminalbloke where I go through making this kind of stuff