When curtains blend so effortlessly with their surrounding decor, you would never guess the amount of time and consideration invested in selecting them. Your room could have an opulent comforter or a remarkable centerpiece, but if your curtains are ill-fitting or the wrong material, they could sabotage the overall unity of your decor.

A major part of choosing the perfect rod-pocket window treatments is determining how many valances or panels you will need for each window. Here’s how in three easy steps:

1. First, measure the width of each window you plan to decorate. Round to the nearest inch.
2. Next, multiply that measurement by 2 or 3 (2 for a moderately gathered (“full”) appearance, 3 for the maximum fullness).
3. Divide this number by the width of your desired curtain pair, panel, or valance. The result should be your ideal quantity.

When deciding the length of window treatments, keep the room you plan to decorate in mind. Rooms like the bathroom, utility room, or playroom are high-activity centers with small windows. Shorter curtains (think a 63-inch length) are practical and won’t get in the way. Stately rooms with bigger windows will need longer curtains (think a 95-inch length). In addition, long curtains can pool upon the floor for an elegant atmosphere.

Another thing to consider is whether or not your curtains should be lined. Lined curtains can block light and save energy but may tread on the bulky side. Unlined curtains are not as energy-efficient yet drape more nicely than the lined.

You can dress up any window treatment and increase privacy by inserting a sheer or lace panel behind your original curtains.

Finally, if you intend to install curtains for your sliding glass or patio door, just remember that these typically come in one extra-wide panel meant to push easily to one side, like an accordion.

Keep these basics in mind, and you’ll get it right the first time. Choosing curtains should be a careful process—not a stressful one!