Your theme development process

Recently, I’ve been thinking about streamlining my WordPress theme development workflow process. It bugs me that it’s taking me months to create one theme. Don’t get me wrong, I love coding, creating and giving my best to building themes and in turn giving the best value for my buyers. And If I must take many months more to release a much better theme than the last one I did, I’d do it. But, practically, shaving some weeks or days from those months of work by following a more efficient workflow would be way much better for me as a developer. As for this, I have devised my own workflow (these are just general points that may change and vary) which, I hope, will make my development faster, so to speak:

1. Theme conceptualization. this includes mock-up designs on paper and wireframes.
2. Design. a more concrete design of the theme regarding layout and aesthetics (HTML and CSS mockup).
3. Development check list creation. a full (and long) bulleted list for checking against various development points like WordPress standards, theme features, possible bugs from last theme, possible buyer requests, etc.
4. Coding. the whole shebang (I think this could really be broken down to much smaller and drilled down modules).
5. Compatibility. for both desktop and mobile.
6. Testing. the most important aspect of the workflow which will I be spending much of the time and in which the Development check list will come in handy.
7. Documentation.

All in all, I think these are general parts and I would like to further refine these points over time and break them apart into much smaller pieces. How ‘bout you guys, what are your development processes?

Regards,
Jan Intia