Besides picking paint colors, the one topic that consistently seems to stump many readers is window treatments. Based on the questions we get asked each week, homeowners are looking for guidance on everything from where to buy them, how best to hang them and what in the world to do with a bay window.

Besides picking paint colors, the one topic that consistently seems to stump many readers is window treatments. Based on the questions we get asked each week, homeowners are looking for guidance on everything from where to buy them, how best to hang them and what in the world to do with a bay window.

To get to the bottom of these questions (and many more), we consulted an expert. Claire Schwab is an Alexandria, Va.-based designer and a certified window-treatment consultant with more than 20 years of experience. We spoke with her recently by phone and asked for her advice.

Q. What's the best way to inexpensively dress a window?

A. If privacy isn't an issue, start with the basics: panels and a pole. They are so readily available now at places like Ikea, Restoration Hardware and Pottery Barn, and they make it so easy. If you can go beyond that step, add a grass or woven shade underneath. The next layer would be adding decorative trim on the inside edges of each panel. You can add the trim yourself with a glue gun or have a dry cleaner do it for you.

Q. What are the most common window-treatment mistakes you see?

A. The one I see most often is not hanging (curtain) panels high or wide enough. Other mistakes I see are: bad measuring, buying retail curtains and not pressing them before they are hung, and not having drapes that are long enough. They should at least touch the ground.

Q. Why should homeowners resist the urge to mount drapery hardware on the window molding?

A. When it comes to hanging panels, we need to go UP and OUT. If you have room to install hardware closer to the ceiling, you should. It has much more impact and gives the room a taller, loftier feel. It also makes the windowsill look bigger, the ceiling look taller, and you're not covering your light or your view. If you are installing hardware yourself, make sure you're using the proper support screws that can carry the entire weight of your treatment. Consider contacting your neighborhood hardware store to see if they have someone who could come out and help you with the installation.

Q. Are there things to keep in mind when buying hardware?

A. You can buy it retail through catalogs so easily now, so I don't think it's that difficult. The one slip-up I see often is when people don't buy enough support brackets. Sometimes you need an extra one for the center so your treatment won't sag.

Q. Do you have any tips for installing hardware?

A. Ideally, you would hire a professional installer who has the appropriate tools for the job. That's what I recommend because I've seen too many people make mistakes. A nice way to hang a panel is to have it return to the wall (meaning the ends turn toward the wall) so it will block the light; an installer will have a special tool for that. They will also have a good steamer.

Q. What are your thoughts on tiebacks?

A. I don't use them. I prefer the long, flowy look. And I think they are fussier-looking. But they are still selling, so someone is buying them.

Q. What's the best treatment for a bathroom or powder room?

A. A combination of a shade or shutter for privacy with a valance for decoration.

Q. What's the best treatment for a nursery?

A. You really have to consider room darkening, which tends to be a mother's priority over function! For that, you really need draperies that have room-darkening lining. You can get shades or blinds with room-darkening lining, too, but the light is still going to peek through the sides. You could do room-darkening shades with stationary panels on the sides to block light from peeking in on the edges.

Q. Floor-length or windowsill-length curtains?

A. Windowsill-length went out of fashion in the '60s.

Q. Should panels end at the floor or puddle?

A. No puddling. It's not as clean a look, and it can collect dust. It's much harder to maintain.

Q. What is the best fabric to use for curtains?

A. Silks are hard to beat because they hang so nicely. Then I would say a medium-weight upholstery fabric because it looks substantial. Cottons and linens wrinkle more easily and are more casual in appearance.

Q. Is there any instance in which a bare window is best?

A. No!

Q. Should all windows in a house with an open floor plan have the same treatments?

A. Not necessarily. But there needs to be one unifying element, and the easiest element is a shade. (For example: If the living room, dining room and kitchen are open to one another), the windows in each room should have the same shade. To delineate the spaces, you can add panels on the windows, using a different fabric for each room.

Q. What is your favorite style of treatment?

A. Draperies with decorative trim on the sides; full, double lining (lining and a flannel interlining, which helps them keep their shape better); and a pretty wood pole.

Q. What's the best way to address French and sliding glass doors?

A. I suggest panels on either side that close and meet in the middle. Those are a lot easier to use on French doors than on sliding doors. You can also put shades on French doors. When clients have French doors in a room with windows, we put the same shades on the doors that we do in the windows.

Sliding doors are tricky. If you can only pull drapes to one side, you'll have to do something vertical. In that case, you can get shutters on tracks, which are framed to fit onto a window frame and move like a closet door. These shutters are custom, so they will be more expensive, but they are beautiful and easy to maintain because you can just wipe them clean. Another option is to have a pretty drapery that stacks to one side and use a valance on top to conceal the movable track.

But I would never advocate vertical blinds. They are cold and very commercial, and they provide no decoration whatsoever.

Q. What's the best way to address a bay window?

A. Let me preface this by saying how tricky it is to measure a bay window. People can really throw money away by taking bad measurements, so consider having a professional at least take measurements. But generally speaking, using shades, shutters or blinds are the safest treatments. You could also use Roman shades on each individual window. If the bay window is shallow, say about two feet or less in depth, I like to install panels on the outside wall, then have shades or blinds on the individual windows.

Q. Do you prefer shutters or shades?

A. I prefer shades when I am layering treatments, and I usually put panels or a valance with them. Shades don't usually stand alone very well.

I like shutters if they are going to be the only treatment. They have a more substantial and architectural look to them, so they stand alone nicely. But pairing panels with them looks nice, too. That's how we did our bedroom. Shutters should always be installed on the entire length of the window. You can order a center divider rail, which allows you to close the bottom for privacy and open the top for light. You can also open and close both at once.

The term "plantation" just refers to the width of the louver (or slat), which is typically two inches or above. The larger louvers have a cleaner look, and you get more light and more view through them. Two-and-a-half-inches is standard. A nine-foot ceiling could very easily take a 3 1/2-inch louver. I typically go with the 2 1/2 or 3 1/2-inch.

Q. How do you handle windows with radiators beneath?

A. I use a shade or blind that stops at the windowsill. If you have room on the wall to go beyond the radiator (e.g., there's no doorway hindering you), I would do panels on either side as well. If you're nervous about heat on the drapery fabric, have a radiator cover made, which a carpenter can do. You can also use tiebacks if you are nervous about the heat.

Q. Which do you prefer for the tops of curtains: pinch pleats, rod pockets, tabs or grommets?

A. My favorite is the French pleat or the goblet pleat because they open up more and are a little more graceful. Pinch pleats are very stiff and really belong under valances. Rod pockets and tab tops are tough because they are difficult to move. Grommets are fine because they can slide; they have a more contemporary look.

Q. What are a few of your favorite retail sources?

A. Gilded Manor (formerly the Curtain Exchange) in Fairfax, Va. (www.gildedmanor.com) They have a beautiful selection at great prices. My second choice would be Restoration Hardware (www.restorationhardware.com). I like their selection, and I think the hardware is beautiful. I also like Next Day Blinds (www.nextdayblinds.com), because they offer measuring and have an in-home program, which can help eliminate simple mistakes.