i start from a very small and timid sketch which should give an approximate idea of the pose. then, on a new layer, i try to improve it working on shapes, contrasts and harmony. during this process i massively use photoshop's transform tool (CTRL+T, then select "Warp"). it is a big help when it comes to exaggerate proportions or move/scale parts (see step 2 to 3). usually i sketch on 3-5 different layers where each one is a step. i learned this method studying animation, where, instead to erase or add too much confusing lines you simply overlap a new sheet of paper on the previous one.
during the coloring process i desaturated the color of the skin to drive the attention to the character's tie. i dont know if it has been a good idea, i just thought it was better to not let too many colors compete.