When you start a website, the temptation is to start writing before you finalize the design of your website. You might have one idea, and it grips you so hard that you just can't wait to get started on it. Well, this may be the only time it is a good idea to sleep on it. Better yet, write down a set of rules for your website. Then anything that doesn't fit in gets thrown out. That's another name for this, and it's called finding your niche.
Finding your niche is akin to finding your voice. To be heard you need find something worth talking about, on a subject that people are interested in. Something you won't get tired of in a few months. This is because you need to create content for your website, and you do this whether it is a personal website or an internet marketing site.
Once you have found the one idea, it gets easier to figure out what your website should look like. There are probably thousands of great looking themes you can use for your website, free or paid. Some themes work better with certain topics, and your theme should fit your subject. While it comes down to your personal taste, a website isn't only about you. It is also about your readers.
I like to think of a website as a magazine. It is about content, and style. With a website, it is also has to be user friendly and easy to navigate. But it can't be about everything, and the narrower your focus is, the better it will work.