When first moving into a home, there is always an appeal to a picture window because it lets a ton of light stream in, gives you a great view of whatever is outside, and gives you a chance to let air flow into the space easily. The dilemma arises when you realize at night time, all of your neighbors can see right back into your house! Luckily, there are a few simple ways to cover the window, depending on exactly what you need the treatment to do.
If after moving in, like I mentioned, nighttime privacy is an issue, you probably want to invest in either a drapery or a shade. A drapery can be pulled across the window in the evenings, and pulled open during the day when you want the openness. The advantage to a drapery is that it does not obstruct any of the window if mounted above, and to the sides of the frame, and also that you have a huge variety of fabrics to choose from , at a range of prices and prints. The disadvantage in this case is that the drapery tends to cover up a portion of your wall, and can appear a little messy (especially if you have kids or pets that can get into it). A shade is great because it is generally compact , think pleated, cellular, or roller , and are mounted cleanly to the inside of the window. Again, they can be closed compactly during the day and lowered at night. The advantages to shades are that they can be mounted as one large one across, or three individuals (if you plan on opening and closing the side windows often), the variety of patterns and colors, and leaving the frame of your window exposed. The disadvantage is when purchasing what generally ends up as a custom treatment, you tend to want to choose a color/pattern that you will love for longer (because you will end up at a slightly higher price point).
If after moving in, the issue ends up being related to the amount of sunlight coming in during the day , tv screen, fading of furniture/flooring , you will want to look for an option that is more light filtering. Again, you can go with a drapery, generally for this purpose you would look for a slightly lighter weight material that more sunshine will filter through. You could also go with a blind in this instance. Blinds give you the advantage of being able to tilt open or closed depending on how much light you want to allow in.
Regardless of what path you chose, there is an option out there for you! Keep in mind that a picture window is generally a statement in the room. While color and pattern is okay, you want to make sure you do not over do it, and overwhelm the space.