How to treat your windows can be a tricky and expensive thing. There are a lot of factors that play into how a window should be treated both functionally and aesthetically. Do you need privacy or do you want as much of your view exposed as possible? Do you get direct sun that needs to be blacked out or just darkened? Does the room have too much going on already or do you need something to soften the architecture? Sometimes you may find your answers contradict one another, and that may mean you need a window shade to do one thing, and a curtain to do another. Economically speaking window shades and blinds can get you a lot of function for the cost. Louvered blinds can control the light as well as privacy. Roller shades on clutch controls can be great for black out or sun dampening. But sometimes shades just are not enough. A room sometimes requires some softening. Drapes when positioned correctly can make a room seem taller, or camouflage defaults.
This image is a great example from Houzz of how dressing a window the right way can accomplish several things at once. The door passage into the hall is much higher then the exterior door, and window are, but this designer has created the illusion that the window is closer in height by raising the drapery rod to the height of the passage opening, and filled in the distance with what looks like a woven Roman valance. Normally a Roman shade would go all the way down. But I suspect in this case it is only stationary, since behind that is the functioning shade that softens the bright sea side light.
Window valances can also be a way to bring in some softness, and a pop of color for windows where most of the time we want full exposure to the view. Shades can be drawn up and hidden behind the valances for privacy when needed.
If you are paralyzed with decorating fear and don’t know what to do with your windows, start with a less is more approach. Address your functional needs in the most aesthetically pleasing way possible. You can always add to it later. And it is okay if the drapes are a simply a shade of you wall color; there is no law that says the fabric has to match the throw pillows. Get Decorating!