The video at the bottom explains - no, shows - what a well-designed set of software tests should look like.
Most test scripts look a lot like this...
If you watched 1,000 American brides walk down the aisle in the 1950's, slight variations on this same general theme would be repeated again and again.
Similarly, if you looked carefully at 1,000 manually-selected tests, you wouldn't find many of those tests that repeated each other identically, but you would find a tremendous amount of repetition from one test to the next. Certain test inputs (like "typical user" or "IE 7" or "select Option A" (or any other common test inputs in your tests), would be repeated again and again in hundreds of tests, for example.
In contrast, powerful and informative test cases look like the next 60 seconds of this video. Click the blue link below the picture and smile while you learn.
Watch the YouTube video. In short, variation is good.