Which in your opinion is the most important primary element of design?

Collecting requirements is the most important primary element of design but not just the client requirements. There are many design requirements that your client doesn't have to know but you need to be aware of, legal or technical constrains for example. 

Thank you, Sidrah

Concept: developed after brainstorming and mind mapping techniques for message, target audience and objectives.

perception: developed using rendering techniques to insure100% percent to convey the message

Lines , Dots and spaces 

First of all, define design, design as business prespective or creative prespective? Second, there is no specific important element, it a sequence of elements which work side by side as a complete process towards the outcome. 

However, there is always a start point and an end, with further more platforms along the process, each platform is considered vital towards a successful outcome.

 .just a good idea with a good Implementation

Piece Of Mind

Concept and Theory.........

"What is required by client?"

Question is vague not clear 

According to me, visual design is a solution to a problem so there will be a simple solution to the problem in any visual design.

The very basic of all visual arts in hand drawing. If You can't do this properly, better find other job.