Urban sketching, line and wash , pen and ink or drawings with a bit of watercolour !
I use a waterproof pen and watercolour most of the the time . I don't like too loose or tight and don't use a ruler. I sometimes use a pencil to sketch layouts. I sometimes do the paint then line over the top or sometimes just leave bits white.
All similar styles but the idea behind urban sketching is to sketch outside and not be too fussy or perfect. Capturing energy and an atmosphere good! When you draw and paint outside the memory of the place stays with you, the sun, wind, scents and sounds. Sometimes I have to sketch from a photo but I try to make those my own if I can.
I've seen some very accurate sketches more drawings really and I've seen some crazy squiggly versions. I'm just trying to find my way and the sketches below are the ones I like best.