The design phase includes laying out the interior pages to some extent, and decisions about where chapters begin (top or middle of the page? right-hand page only, or wherever they fall? new page, or continuous?).
The primary design element of your book, though, is the cover.
There is a lot of talk in the self-publishing industry that sounds a lot like “never allow anyone but a professional book cover designer to design your book’s cover.” Well, poppycock. Balderdash. Nonsense.
In other words, I disagree.
Now, I’m not saying you should use your kid’s drawing from the fridge, or that you should do it yourself if you really don’t have a design bone in your body. But you are not selling this book in a bookstore, competing with fifty quillion other titles. You do not need the benefit of 6,000 years of psychological research to get exactly the right shade of red to properly augment the word “Regiment” in your title. You are not using traditional publishing, nor will you be using traditional publishing’s selling methods.
You will be doing all the marketing, all the selling. Your book’s jacket does not need any more attention than your own jacket.
You buy your clothes; you don’t make them. If you had the skills, and knew exactly what you wanted, you might. Most people don’t (have the skills, or know exactly what they want). Most of us buy clothing designed and made by someone fairly competent who mass-produces stuff that’s pretty good and serves the purpose.
But do you have a professional tailor custom-make every item of clothing you wear, in order to have the best possible marketing for your most important product—you? I doubt it. But, if you do, then by all means, have a professional book cover designer design the cover of your book.
If, on the other hand, you find that a suit off the rack, a coat and slacks from the department store, or suspenders and cargo pants do the trick, then you’ll do just fine to have someone with an eye for design and a little bit of skill put together a book cover. Make sure you get all the elements on; analyze the cover of that book you were looking at earlier for things like printed price, bar code and ISBN, author’s name and photo, description, title, all that stuff.
And finally, finally, we get to print something.