Understanding the product, the customer, and the problem to be solved, is key to owning the design process. Anything else is just expensive guesswork.
The user should always be the first consideration. In my experience, wireframing, prototyping and user testing are the cornerstone of developing any digital product.
I believe to understand digital design you need to have worked at the coal face. I built my own designs for many years, and worked with front and back-end developers on large scale solutions.
I have been designing intuitive user interfaces for over 10 years. I am experienced with responsive sites, enterprise applications and SaaS models. Bad design is my enemy.