When it comes to theme design there are several critical factors that will make-or-break the success of your theme. Here is a look at those that I consider to be the most important.
Blogs are all about content. Since the content is the focal point it's absolutely critical that visitors are able to easily read it. Using harsh color combinations, very small text, poor spacing and narrow content areas can all decrease the level of readability, and ultimately will lead to fewer visitors actually reading the content.
When building a blog theme, make it priority to create a template that will encourage visitors to actually read the content by making it easy on them. A large part of the responsibility for readability will fall on the blogger, in terms of using short paragraphs, bold text, bulleted lists, etc. However, the theme designer can help by using CSS to set up plenty of whitespace around headers, between paragraphs, and around the sides, top, and bottom of the content.
Most blogs use a fairly similar navigational structure, and blog readers tend to expect and anticipate this type of navigation. Sidebars typically contain links to category pages, recent posts, popular posts, and RSS feeds. Most blogs also have a primary navigation bar, usually at the top of the page, which will include links to the most important pages on the blog.
Because visitors expect these navigational elements and they know how to use them, it's good for theme designers to develop the navigation accordingly. Navigation is sometimes used creatively or experimentally by designers, however, that can sometimes hurt the usability of the blog by confusing visitors. If you are going to stray from the typical blog navigational system, it should be clear to visitors how they can find what they are looking for.
With millions of blogs online, and more being launched each day, it's critical for blogs to have an attractive appearance that helps them to stand out from all of the others. Most blog themes are fairly simple because the content is the focal point, however, simple can still be attractive. Other theme designers attempt to create a more unique look that will allow them to stand out.
Especially if you are attempting to develop premium themes, such as the ones being sold on Templamatic, appearance is important. With so many free themes available, bloggers will need to see something in yours that makes them feel that it's worth the money. Typically, appearance is one of the leading factors for that decision.
Each blog has its own personality and its own unique style of content. The appearance of the blog should complement the content and should promote a consistent message to visitors. You can see good and bad examples of this throughout the blogosphere. A good example would be I Love Typography. Because the content of the blog is focused on typography, it's only fitting that the design should also rely heavily on typography to create an attractive look.
When you're designing themes to be used by multiple blogs, such as free themes or premium themes, you really can't control who will be using the theme, so the consistency is somewhat out of your control. However, you can design and develop the theme with a particular style of blog in mind. When the right bloggers choose your theme, the consistency will be present.
Because blogs contain such a huge amount of content, some of it will naturally get more attention and will be given more priority than others. For example, compare the approach of a magazine-style theme to the traditional blog theme. The whole reason for using a magazine-style theme is to feature a greater amount of content from the front page, rather than just giving one post (typically the most recent) the priority. A magazine theme may easily give 5 posts or more a chance in the spotlight on the front page. Magazine-style themes work well for some blogs, but they're not a good fit for the average blogger, because they're unlikely to produce enough content to make the magazine style work.
When developing a blog theme, consider how some content will be given priority over others. Will you include a popular posts list or recent posts list in the sidebar? Will you show full posts or excerpts on the front page? Most of the time the blogger will determine which content gets priority, but the theme designer should make that possible.
Too many bloggers ignore search engine optimization when they choose a blog theme, and too many theme designers don't put enough effort into building a search engine-friendly theme. Not all themes are on the same level in terms of SEO. By taking some extra time in development to build a theme that will give the blogger the best chance of ranking in the search engines, you will be well ahead most other theme designers.
A theme will never create top search engine rankings on its own, but a poorly-constructed theme can cripple a blogs chances of ranking well.
What's Your Opinion?
As a theme designer, which elements do you focus on, and which ones do you find to be the most critical?