Here's your typical packed bike rack on the streets of Amsterdam. Compositionally, the challenge here is how do you make order out of chaos? By grouping the patterns in clusters, i.e. the handle bars and tires, you can reduce the composition into a simple triangular form created with the bars and tires. The sparse background also helps. An improvement to this photo if I could do it again would be to have even shallower depth of field to throw the background more out of focus.