The client is always right - right?

You and I both know that the client isn't always right.  There are times when they are wrong - maybe the misunderstood, didn't hear correctly, or just are being difficult.  The problem is - if you want them to stay your client how are you going to convince them they are wrong?  My thought - your aren't.  That's not to say you tell them they are ignorant, difficult and you would be better off without them (OK sometimes that is the truth, but be prepared for them to become a lost client at that point).  You need to help them understand what happened.  Here are some steps to try:
1. Listen to them.  A high percentage of time they just want to be heard.
2. Ask them what they want.  What they want is usually a lot less than what you think.
3. Do what you can to make them happy.  Help them to understand that you can't give everything away for free - but you value them and want to help make them happy.
Usually you can avoid these issues by listening to what they want before hand, tell them what you heard, write it down, and then have them sign it. It slows things down (something I hate to do) but can save you a bunch of pain later.

Meetings

It is amazing to me how valuable in person meetings are, and how much sales people avoid them.  Sure phone calls, text messages, emails, tweets, etc, etc etc are good, but nothing in better than an eye to eye meeting.  Shaking hands, having small talk, and just getting to know each other.  I really don't see myself in sales, I build relationships that hopefully last a long time.  Along the way, if there is something I can sell that person that might make their life easier, well that's great!