http://nofilmschool.com/2016/02/7-things-to-avoid-doing-if-you-want-keep-your-videography-clients
It is very important to keep clients and to do that the client needs to be happy with you and you work. The client hired you because they believe that you are going to do a good job.
1) In order to keep clients you need to understand what they want or what they would like to have. In order to do this it is a good idea to put together a mood board of some sort in order to find out their likes and dislikes.
2) Find out their likes and dislikes in order to fit your work to their needs and wants. Give them back what they want based on what they already like. Make it about them not you.
3) When things don't go as planned just embrace it and start looking outward to find a way to fix it. Stay positive.
4) Give them what they want but also give them something else that they wouldn't expect to like. Try different things because taking chances may help you keep the client.
5) Post your stuff to social media. Get the client and the clients friends excited about the work you did for them.
6) Be the first one to reach back to clients. Impress them with how fast you can get their stuff done.
7) Reach out to them even after the job is done. Send them a thank you card or gift. Make home remember you, don't let them forget you.