Two Stage Edit
This is often the best way forward. I will look at your book in depth and give it a thorough copy-edit which will include elements of developmental editing and then return the manuscript to you so you can consider my changes and suggestions and make further amendments to the manuscript yourself. You will have an opportunity to talk to me at this stage, if you would find that helpful, although it is not essential.
Once you have had a chance to work through the book again yourself, you will return it to me for a second edit to polish each sentence and ensure a coherent whole. This two-stage process can take two or three months or even longer, depending on how much time you require to consider the first edit before returning the manuscript to me.