All my shots are taken in Raw these days, so they'd look pretty crap no matter what the photo without PP.
Apart from the usual stuff like contrast, colour, adding a vignette etc, except in the following images, some extra bits;
#2 used an effect to turn the image black and white, but called solarization, it's an effect you can do in the dark room with black and white film. Makes parts of the image look silvery. You can see it on the way the cup looks a bit metalic
#4 In photography in the dark room, you can do a thing called dodging and burning. Well in the metalic object, my finger prints were showing in the darker part of the reflection. This wasn't what I had intended, so in photoshop I used the burning in tool to darken the silhouette of the building.
The hand has that warm glow because the sun was setting. I was lying down on my balcony with my one hand up in the air for that shot haha.