[masswerk]

I have the condition, as well (that is, I may have a short visual flash or broad impression, but I can't sustain this), still, part of my work is working as a designer and I'm considered proficient at drawing. It really comes down to classic poetics and relying on / trusting your gestures, while you are drawing. The amazing thing is that you can produce a stroke, you couldn't have thought of in a controlled way, and you're kind of surprising yourself. (I believed for a long time, it would be like this for everybody.)

BTW, this may be related or not, but I have learned to detest gesture based UIs in apps, and, since this has become the prevalent form of control, I've removed about all apps from my phone.