From what I have seen, it doesn't seem to occur to most indie film producers to particularly try, either.
Note the common lack of an Art Direction forum on most indie-production-related sites. There isn't the interest to support one.
And yes, sound is another biggie. People for whom I shoot small projects marvel at the amount of time I spend barking at assistants to locate and disable/insulate sources of extraneous noise.
How much Art Direction do you think someone could do on a 10K budgeted feature? That wasn't snide or passive aggressiveness, by the way, it's an honest question.
Are there tips or tricks you know of or can offer? Some insight? I'm definitely NOT an Art director... lol.