If you are going to self-publish your book, it is critical that your book's cover attracts attention, fits within your book's genre and looks good no matter what size it is (due to online marketing and sites like Amazon).  Here are some tips to help you create a book cover that grabs attention:

First of all, research other books in your genre for ideas. For instance, you'll notice that a modern "chick lit" cover often has a fun and curly font and pastel colors.  Horror novels often use a "deconstructed" font with darker colors. Whatever your book's genre, you'll want to use its basic elements for easy identification.

Don’t use more than two different fonts on your cover – and you should think of bold, italic, underline etc. variations as different fonts.  More than that and things start to look cluttered and hard for the eye to focus.

Put your title somewhere in the top half or third of your cover (also called "above the fold").

White backgrounds will disappear on retailer’s white screens. Use a color, a texture, or a background illustration instead.

Find supporting images that evoke a mood or tone of the book- don't be too literal. And don't skimp out on the image by using a tired piece of clip art or an overused sunset or beach.  Sites like iStockphoto.com are great for finding high quality images that you can purchase for your cover.

People read left to right, top to bottom in the Western world. So, position your cover's elements in the appropriate importance.  Sometimes you'll see novels where the author's name is at the top, but that's usually reserved for popular authors who can sell their books based on their names alone.  The rest of us need to have the book's title sell for us, so it's usually at the top.

Think of your book cover as a billboard that's trying to attract the attention of drivers as they speed on the highway. Billboards usually have fewer than 7 words for a reason. Sometime long book titles work, but most of the time they're 1, 2 or 3 words.

Reduce your finished cover way down and give it the "thumbnail" test. Make sure it's easily readable when drastically reduced for display in online bookstores like Amazon or Barnes&Noble or in the Kindle shop.  Also, if you're using your book's title for other online marketing, you'll be using a reduced version on Facebook, Twitter, your website and other platforms.

In a bookstore or anywhere that you'll be selling your hard copy, the viewer will first look at the front cover and then flip it over to the back cover to read further. The back is often almost as important as the front. 

Hire a graphic artist to help design your own book cover.  Many printing companies that specialize in short-run printing also have a designer on staff who can assist you. Alta Graphics has several "Design Packages" to help you get a great design on a budget Alta Graphics Book Cover Design Packages. Designers, like editors, can be worth their weight in gold. Your designer will be looking to you for direction, however, so make sure you do your research before you begin so you don't use up lots of hours making revisions.