I found this post on Fabulous after 40. I list this site in my favorites so take a look from time to time for great fashion advice. Here is a portion of Debora's advice so be sure to read the whole article.
There’s been a lot of confusion about skinny jeans versus leggings. Many of you have emailed to ask what the difference is between the two, and whether you should wear the same kind of tops with leggings that you would wear with skinny jeans. So here’s some general guidelines.
Skinny jeans are tight pants that narrow at the ankles, often hugging them. The best skinny jeans have some stretch built-in.
Leggings are more like tights or thick stockings. They are very soft and very stretchy, as well as form fitting to your body and end at the ankle or mid-calf. They are also much more lightweight than skinny jeans.
Can You Wear the Same Tops You Wear With Skinny Jeans with Leggings?
Since skinny jeans are considered pants and leggings are an accessory, what you pair them with is different.
Jeans are heavier and thicker and can be worn with short tops. Leggings are thinner and lighter and should be worn with a top that is long enough to cover your crotch and your bum. For example, you need to wear a shirt, long sweater or tunic with leggings, or else you will reveal too much information, especially after 40!
There is also something in between called jeggings; These are a cross between a legging and a jean. They are a skinny jean with a lot of stretch. If you have a good figure, you can sometimes wear jeggings with a shorter top.
With so many slight different styles of skinny jeans and leggings out there the line has become very blurred. A good mirror is your best judge.
Be sure to read the whole article where Deborah shows 4 different looks. Also More information here: