It is worthwhile to have one or two expensive pieces to set the room but the rest can be fun, inexpensive and versatile. Here are a few of my suggestions and starting with the most expensive.. click on the links to find current pricing.
For the expensive elements, I suggest owning a good quality soft cashmere or abaca throw. It will look great, last through use and be special for you and your guests. I recommend the Hermes Signature H Throw. It is classic, timeless and super comfortable...expensive but worth it.
A Shagreen Decorative Box. This antique box from Modest Designs is wrapped in shagreen with an ivory border and inlay. France c 1930.
While Tiffany's is obviously known for their jewelry, they have just a few home accessory items that fit the bill...wish they had more. I love this Elsa Peretti Thumbprint bowl, infact, I have a large one in sterling silver at my kitchen and a small cobalt crystal in my bedroom.
Pillows can be more expensive than people realize but a good decorative pillow goes a long way. You'll know once you have purchased the difference. You want to be sure to get goose down pillows (or inserts). Here are a couple cool pillows. The first is a hide pillow from Jason Home and Garden. The second are Belgian Linen Knit Pillows from Restoration Hardware soft, have nice colors and can be mixed and matched.
Mirrors are a great accessory and can open up a room or just show a beautiful reflection. This simple, clean lined floor mirror with its aluminum frame from CB2 can go in any room.
Candle Hurricanes are perfect for indoor and outdoor ambiance, I don't think you can have enough of them. These hand-blown crystal hurricanes from Lucca have a smooth look and are suited for both.
These ikat woven baskets from West Elm are attractive for storing blankets, laundry, magazines, plants or on their own.
Books are a another great accessory and you may have some of them already but they are just tucked away. Stacked vertically with a cool pair of bookends or horizontally with an object sitting on top. Group a few books that have hardcover and similar size; stacked equally on sides. If you don't have good substantial books then they are a great purchase. So called coffee table books can be of any interest you may have such as photography, art, travel. For example, a of Picasso from Philippe Dagen ..
Both the blue/green (on the far left) and the white (on center) make interesting vases for flowers. I like using wide diameter vases and creating a full bouquet. Some of my favorites are peonies.
And lastly, just can't say enough about candles... I love these Diptyque candles from Paris..