There are a variety of ways to customize your blog so it doesn't look like a standard template. You could hire a blog designer
for a complete blog makeover or you can tweak a blog template to make
simple but highly effective design changes. Don't worry if you're
technically challenged and not comfortable modifying HTML or CSS
code. Blog designers offer the simple design changes listed below at
much lower individual costs than a completely customized blog design
costs. Use a free or premium theme and use the quick blog design tricks below to make your blog stand out from the crowd!
1. Blog Header
Your blog header is displayed at the top of your blog and is the most prominent part of your blog. It instantly communicates what your blog is about, so it should be well-designed. Blog headers can include text, images, or both.2. Blog Background
The background of a blog displays when the content columns don't fill a visitor's full computer monitor screen. Usually, the background can be seen flanking the theme content columns (the posts column and sidebars). You can choose any color for your blog's background or upload an image for your background.3. Blog Colors
You can change a variety of blog colors to create a consistent, branded look. For example, choose a color palette of 2-3 colors and change your blog's title text, link text, background, and other elements to use only those colors.4. Blog Fonts
A blog filled with dozens of different fonts looks sloppy and creates the impression that the blogger doesn't care much about the user experience. Choose two primary fonts for your blog and use those fonts (and bold and italic variations) for your title and body text throughout your blog.5. Blog Post Dividers
What's in between the blog posts on your blog's home page or archive pages? Is there just a bit of white space? Maybe there is a single black line that stretches across the column? A quick trick to make your blog look better and unique is to use a custom post divider. Post dividers can be customized simply by changing the color of the rule between them or you could insert an image as your post divider.6. Blog Post Signature
Many bloggers like to sign their posts by inserting a custom signature image. This simple image can add personality and uniqueness to your blog.7. Blog Favicon
A favicon is the tiny image that appears to the left of a URL in your web browser's navigation toolbar or next to website titles in your browser's bookmarks list. Favicons help to brand your blog and make it seem more credible than blogs that use the generic blank piece of paper favicon.8. Sidebar Titles
Don't forget to dress up the widget titles in your blog's sidebar. Change the color and font to match the rest of your blog as well as the personality you want to give your blog.9. Social Media Icons
There are tons of free social media icons available that you can add to your blog (most often in the sidebar) to not only invite your audience to connect with you across the social web, but also to add some personality to your blog. From simple shape icons to fall icons, there are creative icons available to add some pizzazz to your blog.10. Blog Navigation Menu
Your blog's top navigation menu can be a simple bar with links or it can be a free-flowing group of links that match your blog's header design. The choice is yours, but this type of blog design customization is just one more way to make your blog stand out from the crowd.
From http://weblogs.about.com