What are the artistic skills and techniques in the process of creation? ?

For me, it all depends on if you're into digital artistic skill, or physical. Digital art creation would be expressing your ideas through the utilization of software, such as Photoshop, premier pro,etc. Physical creation would be classic hand painting, drawing,etc. They are majorly different in style, however, in terms of technique, they do have things in common, such as obeying obeying golden ratio, Pi rule,etc. Also, at the core, careful observation of real world objects and events, and transcend them into an art form is an essential part of art creation. Art is not reality, but it's a transcended form of reality. Remember that.