Sounds to me like you jumped into the deep end of the pool. Always glad to hear about new quilters finding us.
I have never made quilts for customers but communication seems like it would be the key. Depending on the individual, some probably want a lot of input while others not so much. There are so many sites available, I would put together a list that a customer could refer to and of course keep pictures of past projects. More than anything enjoy the process. Hope this is the beginning of a long and pleasurable journey.