Maybe I qualify to respond; I am a web designer.

My web design business is the fourth food group of my GTD life. I am a full time student; I work two part time jobs on campus; and I am married, trying to maintain a home life. Business is both extremely important to me and not the highest priority at the same time. So, GTD is important for my own sanity and overall wellbeing.

Of course, as I'm sure you have figured out, the hardest part of applying GTD to creative endeavors such as graphic design or web design is breaking projects down into true Next Actions. The stock answer is that GTD helps manage the business side of things so that you have more time for the creative stuff that is by nature more free form.

Personally, I think GTD has helped me with the creative aspects of my business. Here is how I tend to do things. (Sample project to follow.)

Project: Create FooBar Website
1. Project questionnaire to client
2. Sketch to brainstorm possible layouts. (->Moleskine)
3. Brainstorm color schemes. (->ColorSchemer studio)
4. Client questionnaire
5. Cp. client questionnaire responses with brainstorming
6. Add from client questionnaire to brainstorm list. (If C already has existing color scheme for marketing, etc., C scheme overrides brainstorming.)
7. Mockups
a. One based on client responses entirely.
b. One based on my brainstorming only.
c. Two possibilities based on the best of both worlds.
8. Client response, selection of mock.
9. Identify graphics that need to be created. (Gradients, backgrounds, etc.)
10. Graphics.each(create();)
11. Setup CMS if necessary.
12. Identify necessary page templates.
13. Templates.each(
Code layout/structure markup.
Code layout/structure stylesheet elements.
)
14. Copy and/or other design elements from client.
15. Site browser testing.
16. Link checking.
17. SEO checking.
18. Submit for client approval.
19. Make any revisions. Goto 18.

Of course, before and after these steps, there are all sorts of NA's that have more to do with the business side of things. So, NA 20 would be Submit invoice. Then, Client payment. Then record payment information, deposit payment (if necessary), Payment to clear (if necessary), Apply payment to invoice, send thank you, follow-up, on and on and on. Also, administrivia such as setting up domain names and hosting.

Of course, I cannot say honestly that I always do this. Nor can I say that I wouldn't simply skip some of the steps. For instance, Identify graphics is something that I can do (and should do) quasi-automatically. Also, I think this is one of those projects that I do so often that I don't have to write down all of these steps on a NA list.

Anyway, hope this helps.