The biggest thing I look for is to be clued in to the feasibility and difficulty of their commission. If someone wants a Facebook clone for $500 and/or finished in 3 weeks, I'd walk away immediately. I guess that's an exaggerated example but if a client is completely non-technical it's almost always too painful to work with them directly.
I don't agree with 'never say no to a customer' in software development work.
I don't agree with 'never say no to a customer' in software development work.