I realize this will not work for everybody all the time. Offer you product for free. Let your users test it. Make this fact known to them. Be transparent and it will show. People love to help, they feel a sense of accomplishment and ownership.
In practice you must provide an extremely simple way for users to provide feedback. The easier it is on them, the more constructive feedback you will receive and the better your product can become once you apply their feedback into you project.
This is a simple concept that is often ignored. Bigger companies will never be able to go this route. Showing weakness is something they will never allow. Weakness to me is taking four times as long to release something. Weakness is not allowing your customers to easily and promptly provide feedback, every step of the way.
How do you allow your customers to provide feedback? Can you improve it?