Of course there are certain clothing items that belong in a specific section of your seasonal wardrobe, there are surprisingly many items of clothing you can keep out year round.
For the fall, it might give your outfit a nice change from summer if you add a few cardigans or shells to your closet. The short sleeve shirt you wore this summer can now have a layer added on the top of it and worn through the mild parts of winter. Changing the outer layer also allows you to add in and use a shirt with different color palates.
Many business women have just a few pairs of pants, skirts, suits, or blouses they own but they are able to reconfigure them with accessories, purses, jewelry, and outer wear to create entirely separate looks.
This is the trick with any wardrobe...be able to exchange your tops, bottoms, and layered pieces. It is so tempting to purchase new seasonal clothing but try to think about what you have and how you can keep using it throughout the year. It will save you money in the long run. If you wear the same 20 tops all year for a year or two, then you can start replacing one at a time as they age. This will allow you to feel like you are always getting new clothes without the expense. If you purchase the whole season's wardrobe new it will be a much harder punch to the wallet.
My wardrobe has two main color palates: black and brown. You can almost always match what I have with black pants/shoes, or brown pants/brown shoes. Even when you get into your navy colors, brown usually will pair up nicely. There are some things that join the brown family that do not go well with black, and vice versa.
Everyone has to have their own sense of style, fashion, and what they feel comfortable in. I am a brunette with a medium complexion, so I wear a lot of nude, brown, green, and denim-navy colors.
Below are some photos of my favorite closet "must haves":
Long sleeve jacket-like layers. A style like this allows you to show all or just part of your top underneath. This allows you to change your look with countless tops underneath.