We’ve been talking about how to build an office-friendly wardrobe that will also work for those hours and days when you are NOT at the office. The goal, of course, is to have a closet full of basics that you can mix and match and wear for years to come. The place to start any wardrobe overhaul is by assessing your existing wardrobe, which includes making a list of pieces that you are missing.

As you go through your closet and try on everything that has survived the purge (pieces that fit AND are in good condition AND are classic enough not to reflect a specific trend or moment that has long passed), you need to take note of what you DON’T have. While you might easily identify gaps in your basic pieces — no trench coat, for example, or no office-appropriate jeans — you also need to think about the details: Do you have the right undergarments for every piece in your closet? The right shoes for every outfit? The right accessories for every look?

That fabulous white shirt won’t look so fabulous if you’re wearing it with a green bra, trust me. Or even with a white bra that shows RIGHT through.

Make two lists as you clean your closet: one list of Big Pieces (trousers, skirts, blouses, dresses) and a second list of Foundations and Accessories (lingerie, jewelry, bags, shoes). These are the things you need to shop for, because these are the things you actually NEED. Nothing else, at least for right now.

Now do some research: if you need dark-wash mid-rise jeans in a size 14, start browsing web sites to see who carries such a thing, how much they run, and what other women say about them. More and more sites are carrying product reviews ON THEIR SITES, which is fabulous; for brands that don’t include product reviews, forums like Ask Metafilter can be a good source of information. Get a sense of what’s out there BEFORE you actually head to the mall. I am convinced that one of the reasons so many women claim to hate shopping is that when you shop for a specific thing, it’s a gigantic hassle to go from store to store to store looking for it. I am also convinced that this store to store approach is the direct cause of nearly all of the impulse buying that we do, and results in closets full of crap no one wears.

Bottom line: make a list and STICK TO THE LIST. But do your homework first, so that you know where to look and what to look for.

Aside: I prefer to try things on before I buy, which makes online shopping tricky for me; I also hate to pay shipping, because I am cheap. Not every store carries every piece offered online of course, but many stores will place catalog orders for you and NOT charge shipping, which is a nice compromise. Going to the store also gives you the opportunity to try other similar pieces on, which will give you a nice sense of how that brand fits before you order, which is also helpful. End aside.

Preshopping on the internet will also give you a good sense of what the items on your list are going to cost, which is important to know before you whip out your credit card. Keep in mind that you are looking for pieces with staying power, so automatically opting for the least expensive version of whatever it is you’re looking for may not be the best idea; a very cheap suit, for example, is probably not as well-made as even a mid-price suit. Use your internet preshopping to get a sense of how much money you are looking at spending, and then use THAT to determine a budget and plan your actual shopping trip.

Be honest with yourself about how much you are able to spend each month, and then spend ONLY that much. Consider taking cash with you when you shop, not a credit card; when your cash is gone, you are done. (But resist the urge to impulse buy JUST because you have cash left over! It’s okay to come home with money in your wallet, I promise.) Prioritize your lists, and start with the pieces you need the most RIGHT NOW. Let’s say that you need both a trench coat and two or three tops that are not t-shirts. Both of those things — the trench and the tops — are going to cost about $200.00, which is your monthly shopping allotment. But look, it’s nearly summer! You don’t really NEED the trench RIGHT NOW. Shop for the tops, and move the trench to the bottom of the list for now.

Now let’s say you luck into a sale, and the tops that you thought were going to cost $200.00 wind up costing $125.00. You can do one of two things: put the other $75.00 aside for the next purchase, or move on to your list of Foundations and Accessories and start building that part of your closet. Either way, stick to the plan: buy only from the lists and spend only what you have budgeted.

In the end, you will have great clothes that work for you, and no debt. And that is totally stylish.

Next week: shoes! Because the right shoe can change your whole look.