Not sure if you have a NY&Co around (they are also online), but they often have really cute "basic" skirts and dresses. If you sign up for their emails, they will send you coupons and alert you to sales like BOGO. I've bought $300 worth of clothes for about $100. I love sheath style dresses because they are so easy to wear. Just add a few accessories and you're good to go! They also always carry neutral-colored pencil skirts, which can be dressed up or down, some pretty, striped, button-down "business-y" shirts and patterned shells which look good with their jackets/blazers.
If you are looking for Cardigans, Old Navy has some nice ones that have a little bit of spandex in them - they are a bit more fitted but not tight:
http://oldnavy.gap.com/browse/produc...scid=476877062