The introduction may appear at the start of your book, but don’t get caught up trying to perfect it before you write the rest of the manuscript. Many new authors are surprised and relieved to find that it’s usually the last chapter to be finalised!
Trying to write the introduction before you start the book is like trying to describe the taste of a cake you haven’t baked yet. How do you know how your cake tastes if it doesn’t exist yet?
Your introduction is really a wrap-up of what you have created; a rundown on what the reader should expect in the book you have written. That’s why it is hard to write before you start, because you don’t yet know how the book turned out. Books change and grow as you write them, and often don’t reveal the nuances of their flavour until the end.
I know many authors want to start at the beginning and have a go at their introduction. If that’s you, go ahead and put together the frame of your intro. Get some points down; talk about what you are planning in the book. Let the reader know what’s going to happen. How is the book structured? How do they need to prepare before they jump in? Will they be asked to participate with thoughts or actions, or can they sit back and relax while you take them on a rollicking good ride from start to finish? What are the concepts you want to share, and how will this affect your reader? How do they feel when they start, and how will they feel when they finish?
Getting your thoughts on the introduction down can help crystallise what it is you are trying to achieve. Then when you have finished your manuscript, come back and take another look at the introduction. Like a diary from a few years ago, it can be fascinating to compare what you thought then to where you are now.