One "general rule" of road cycling fit is that you're hips don't rock back-n-forth as you pedal; i.e. ensure your saddle is at the appropriate height for your leg length.
From what I've gathered ... there are many opinions about this. Some say whatever is comfortable for you determines what your saddle height is; others say get the "fit" and leave it alone (unless you have issues, of course).
My position on this is as follows:
1) like all "rules" or "guidelines" they are intended for the average person (is there one?) whereby most people will benefit from adherence.
2) if you're new to road cycling, you should be "fit" to your bike by your fav LBS and start from there paying attention to how your lower back and knees feel after long rides a few weeks later.
3) if you have not been fit, you'll have to gain experience only by cycling and paying attention to your body ... keeping in the back of your mind the possibility that your saddle is not at it's optimum position for your body and style.
4) if you've been cycling, fit to your bike or not, and you've had no physical issues and are satisfied with your performance (power, etc.) ... then leave your saddle alone; even if I mention that your hips are rocking back-n-forth.
Here's a discussion that meanders back-n-forth on this issue: