When writing a book, do you try to get a publisher before beginning or after?

Any other advice also welcome.

Hi. You can try prior as it does motivate you. For my first book; it was 10yrs before publication despite it being an original idea. The book was publishable but the main field , would not sell enough copies. Try and get a good publisher- mine folded soon after so I never receive any payment despite it still selling.Also log the book with a copyright registration agency on line as I nearly lost my idea to several people and publishers. Good luck and do not give in!!

Thank you for responding and for the good advice.

PS. Publisher will expect a full proposal and chapter outlines with full refs.This can take considerable time. I do not know your field but if I can help, just send me a message. It is best to have experts to review-- I did have a couple and publisher may ask you to name some. I wrote mine alone and it was rather lonely. Thanks

It wouldn't be a book related to my PhD or academia.