Sigh, the word train. You know they do that to trees, right?
Anyways, there is no "right" answer that I've found. When I started everyone said "don't be so strong." Then 2 years later a 6th dan wandered in and suggested that I should use more strength. Aaaaaaggggg.....
You can literally practice in a dojo, walk across town and they will tell you something exactly the opposite. At one dojo it's be strong, at another it's be centered, at another it's be soft and flowing. And they are all right--for what they are doing.
Listen to yourself. If your careful with that, you'll know what to work on.
Other than that, there is no right answer, although Chuck's "if they can do it" feels pretty right.