How to design a book cover?

With increased self-publishing opportunities, many authors are wondering how to design a book cover. Book covers may be judged as works of art by critics like NYT book reviewer Joseph Sullivan, but they are primarily an advertisement for content. What does book cover design entail?

Book cover design basics

Overview
Covers convey basic information about the book. Who wrote it? What is it about? Why does the book shopper need to buy it? It also carries registration (ISBN) and pricing details.
The title usually is the most prominent text on book jackets, although the author's name may dominate on a fiction book.
Size, font and colour influence book buyers.
The International Standard Book Number which you obtain online is grouped with the pricing bar code.

Back cover text

Description
Remember to design the complete cover as one.
The design has to stretch leftward across the spine and the back with the main focus image to the right, which will form the front.
Approximately one hundred word promotional 'blurb' summarises the content and fits in the top section of the back cover. Use a very short author's biography above the blurb panel on non-fiction to show their qualifications to write this book.
Brief review comments can be placed below the blurb.

Colour scheme and image

Images
Select the main image, deciding whether a photograph or drawing works best. Image dictates genre even more than colour or font.
Fiction depends on attracting a reader through symbolism.
The colour that most often occurs on book covers is blue.
This must imply that readers are attracted by blue, so it is well worth considering. Lettering needs to be eye-catching.
Against a dark background light-coloured text looks clear, but a pastel background could be different.

Electronic books need cover designs

Covers
Many authors self-publish online find that simple software for their PC is adequate to produce cool covers.
E-book purchasers choose from thumbnail sized book graphics in online bookshops, so make sure your design looks good enough small to wow any book browser into buying.
Ordinary photo manipulation software should be sufficient for designing a straightforward book cover.
You can download one free, from such as Piknik.com.

Book cover design software

Softwares
Buy downloadable specific book cover generator software, through BookCatcher.com for instance, or from BookCoverPro.com.
Alternatively, download free software from MyeCoverMaker.com or from another similar site.
This is more complicated, and requires some investment in learning various techniques, but the result looks very professional.

Keep it clear and simple

Final word
With computer graphics so accessible and easy to manipulate, it is tempting to throw too much into the mix.
A crowded cover will not sell well.
If you can't make a success of it yourself, software designers or artists often provide a book cover design service at modest cost.