Thanks much guys!
@THW : probably because of my old age
@ Diamond : I should have thought of it during the process :/ but really nothing really hard to here. For buildings blocks, basically outlines are done with a lightgrunge round brush, added a shadow by hand with a darker line, filled with color on two layers. then added some pattern in the color filled block first layer with blending mode layer option(adjusting blending mode and opacity). Then selected the color blocks layer, reduced, feathered and erased the selection so that you could see the second colored layer underneath.