My friend Paul came over the other night and he showed me some of the projects he’s working on right now. I asked him to explain his process to me when working on a client’s project.
The core piece of communication is content. From there, you work out typography and all of the styles, including size variations; colors; iconography styles; art direction in general.
After briefing with the client at this point, you can gain more insight into what’s working, and then continue iterating.
He showed me http://codepen.io where he designed a few different button styles, to see how the button functions and how the user interacts with it.
I wasn’t able to grab an example from him directly, but found a similar one on Dribbble.