We start thinking on interface solutions from Wireframes. This stage is good for brainstorming. It means that we pledge basic principles for work interface and test user behavior before we spend a lot of time on look and feel. As result we have strong skeleton.
Before start work on look and feel we make research of last win solutions in design industry. We decide where it's good to set up accents and how color palette and graphic elements will help to use interface. Also we work on typography and spaces for better understanding of info blocks.