If you want a good relationship with your client, you first need to earn their respect. Of course, you need to respect them too.
You can not expect the client to respect you for the companies you have worked for, the company you now work for, how much experience you have or how well you know someone who knows your client.
You need to earn your clients respect by accomplishing something on that job.
It is the same when you are building relationships with your managers, your colleagues, your suppliers or your team members.