The essence...

of dress-sense is

You should always take time to think about whatever you want wear and aim to “Always Be Confident.”

To "Always Be Confident," you need to "Always Be Comfortable."
To "Always Be Comfortable," you have to DRESS well. 
DRESSing well entails wearing clothes that are:

Decent not distasteful - so you are never holding up or pulling down parts of your outfit;

Reflecting God’s glory not revealing your body - they should be fitting nor flirtatous;

Elegant not necessarily extragavant - clothes don't need to cost a lot to look good;

Suitable not just stylish - don't spend money on stylish clothes that don't/won't fit you;

Simple not stuffy - a lot of times, less is more, accessorize sensibly.

As you think about what you'll wear each day - remember it starts with ABC.
I looked around found some other tips: http://www.ehow.com/list_7570050_tips-good-dressing-sense.html
http://www.debenhams.com/webapp/wcs/stores/servlet/contentView?filepath=/DebenhamsUKSite/Static/Buying_Guide_petites_uk.xml&storeId=10701&langId=-1
http://suite101.com/article/10-simple-style-tips-for-women-a43048
My takeaway from all these and other tips is that: "The essence of  of dress-sense is to always look graceful...and it starts with ABC.