I'd second (or third) the suggestion that you look online at various retailers' offerings. Then go someplace like TJ or Target (or to your local department store when there's a sale...and there's almost always a sale) and see if you can replicate it. But I'd put quality over quantity if you can.

I've struggled with professional-ish wear myself. I'm an attorney, so I can't wear jeans or khakis as a general rule. I bought a number of suits and dress pants at one time, but I quickly grew to hate them. Styles seem to change rather quickly and dress pants can be very unforgiving when you gain or lose even just a few pounds. I'd add that a lot of retailers just stopped selling much in the way of suits. If I wanted to wear black 4 days a weeks, I'd be set, but I don't.

The answer to my dilemma has been the knee-length skirt. Pencil or A-line. Granted, I'm not sure my boss thinks (though he'll never say this) that I'm dressed up enough, but I honestly don't care all that much. In the summer, I pair the skirts with nice sandals. In the winter, it's tights and boots. I wear a lot of sweaters, summer and winter. I tend to spend more on my winter wear. Because they're often wool, the pieces will last a long while if I take care of them. I don't buy anything overly trendy and I stick with things I can mix and match. Most of my skirts come from Boden.com. The skirts are just "fun" enough in their design to seem youthful, but the cuts and length are generally work and age appropriate (I'm 42).

As for how to take things from your old wardrobe. First off, get rid of anything that just doesn't fit well. Second, look for cuts that are pretty classic. Pencil and a-line skirts never go out of style really. Stick with knee-length or just above the knee. Flat front pants, especially those that aren't tapered, hold up well over time. Cardigans, crew neck and turtleneck sweaters are usually timeless as well. Third, get rid of anything that is worn, faded or otherwise showing its age. Once you pare down your existing wardrobe, it might be easier to see its potential. Update your shoes and get some new accessories (perhaps some jewelry and some new handbags), and you could easily breathe new life into your old wardrobe.

Just as What Not to Wear emphasizes, fit is everything. A trend isn't worth following if it doesn't flatter your body. I know tapered pant came back into style recently, but I'm short with heavier thighs. Tapered pants do nothing for me. So, I don't care how "in" they are; they're out for me.