Look at every interaction you have with a client as a chance to get more information and feedback about your brand – whether you're asking them for feedback at that precise moment or not.
Initial conversation with a new contact: Pay attention to their reaction when you talk about your business. Do they get excited about certain phrases? Do they seem confused? Do they instantly want to talk to you, or do they take some warming up?
Sales conversation with an interested prospect: What questions do they ask? Are the questions about whether your services fit their needs? About your process? Are they just concerned about price (which is an indicator that your marketing materials don't talk enough about value, or give them any concept of whether they can afford you).
Intake conversation with a new client: Again, what questions do they ask? What have you left unanswered? Are they still wondering if you're right for them? Do they make any comments about what convinced them to go with you? What are the biggest concerns that you can get out of the way early in the relationship?
Emails and phone conversations during the project: Look out for compliments and criticism of your manner, process or services. Look for any spaces where you can alleviate confusion as well.
Project sign-off/ delivery conversation: Find out about how their experience was, ask about next steps with you or for their business in general, and do a project post-meeting to see how you can improve.
Testimonial: Read all the testimonials you get carefully – there can be gems of information about your brand and your perceived differentiators in there.
Referrals: Ask new clients where their referral came from, how it came about, and what they've heard. You never know what they'll have to say!