Yes, simple design is hard, it is difficult to find that balance of style and substance. It is easy to add the latest wiz bang web fad to your website to be cool. Trying to make it simple to view the content and pleasant to look at is the key. The absence of stuff can be just as powerful as the addition of stuff.
Balance
That balance is very tricky, I really tend to add too much gimmicky web components to a site. Then I trim it back, re-think how I can present the same content in a cleaner fashion.
Negative is Good
Negative space is a good thing to have. The areas between elements can be just as important as the element itself. It is more pleasant to the human eye to see less clutter on a page. I strived to achieve that on this site, resisting the urge to clutter the pages with too much information. Spacing the header text from the paragraphs and images is key. Plus, having sections on the page that is just for a particular piece of information is important also.
So, keep it simple, it is difficult but worth the effort.