Know what is most important and what people use. Based on user interviews track what features are most needed. See what features users even care about or need. Track what buttons are being used. If the customer has an idea, ask why they want it and what would that let them do?. When talking to customers, ask questions, listen, don't interrupt, be quite. Talk to customers that hate it. They will be able to tell you what you are doing wrong and how to improve it. When you finally get someone on the phone to talk about your product, remember to shut up. Tell them you are testing the app, not them. What to do:. Watch their screen to see what they do. Don’t answer any questions. Give them a task. See what they are confused by. See what buttons they are using. Questions:. What do you use it for?. What do you need?. What isn't working?. What are you confused by?. What do you struggle with?. What would you like to use it for?. What do you wish it could do?. What do you care about?. Any ideas for improvement?. Any ideas for what could be helpful for first time users?