Maybe this is a form of "moving meditation", because even though i think, i think of nothing. Thoughts wander in and out and i feel contented that i can be silent. After such moments it makes me think of those articles about "finding time for silence", where you have to practice it. You know, tell your friends and family that for 24 hours you will refrain from talking. It becomes a big deal and an inconvenience to everyone involved. Talk if you must, but when alone just stop.
Now what does this have to do with art?
You can take the same approach to art. Listen tot the inner critic, but don't necessarily respond to it. Be silent and just let the line work. let the drawing happen, and if the image isn't right, try again. I've gotten my most profound leaps of skill with this method. It's like when astrophysicists say they spend days/weeks/months/years trying to solve a problem, but the day they decide to give up, that night their dreams figure it out for them. and thus they can continue in the process. That's how it can be with the pencil/pen/brush.
So this is how it goes:
You listen to the critiques (wether your own, or other peoples); You think it over (trying to process all this new information); You shut up (stop thinking about it, don't listen to the same critiques over and over again); Then just do (just do it, like the Nike ad!)
And what does this have to do with Zen?
Well by accepting (and this is going to sound new age-y and cliched) the noise around you but not necessarily contributing to it, you end up striking a balance. Like the reed in the water (one of my favorite metaphors). The noise bends you one way or the other, but never breaks you. and for not straining to remove yourself from the noise, not make more noise yourself, you don't rip your own roots out! Does that make sense? Zen is about learning to be present in every single moment. and in this day and age and culture of city life, it's hard to find silence. But even if i lived in the country I'd still hear: winds, animals, plants, rain, etc. and those noises can be just as distracting. So learning to allow the noise to be around you, but not necessarily affect you... learning to shut up every so often both internally and externally, without the need to lock yourself up in a padded room or box, will, I think, make you calmer and thus happier. And who doesn't want to be happy?