3) This progress uses a lot of time to fill the details. Zoom on the image to fill details in every part to get the clear object. And I fill the details until I am fully satisfied. In some parts of image use the reference image for help in painting. Depend on the experience and basic of art that you can practice. Now days you have many tools in programs but you should use specific tools that suits with you. When you are more skillful or experienced then try to use new method together.