Every window should have an opportunity to become its best self. Windows add light and ventilation and sometimes a great view, but not always. That said, you need to determine how your windows will function best for your room and your needs.
First assess where the window is in the room; is it on the north, south, east or west wall? Then, you can move on to what effects north, south, east or west light and ventilation will have on your room. For instance, if you have a view, you will want to capitalize on it-- nothing trumps a view. If your view is to the south or west, you will have sun issues that need to be addressed to protect your furnishings and floors; consider tinting so you can enjoy the view.
With a view window, you may want to consider no window coverings at all which will work if you do not have a privacy issue or need thermal protection; tinting will also help with thermal conditions. In the case of a view without the need for privacy measures, I usually recommend nothing at all, or “dummy panels”, non-functioning drapery panels that add color, design and interest to a room to enhance the view outside and the decor of the room inside.
If you have a window without a view or an unpleasant view, I usually look outside to see what can be done to alter the view. A block wall is decidedly uninteresting until you plant a clinging vine on it, flowering or not. However, beware that non-flowering vines usually are deciduous, turning red in the fall and dropping their leaves in winter, leaving a skeleton of branches on the wall. If planting will not work, I suggest covering the glass with a semi-opaque film, then adding pretty drapes or blinds. You want the light, but can avoid the assault of an unpleasant view.
Odd shaped windows are a challenge and usually require custom coverings; those can be expensive. Again, consider the above solutions if they apply. Custom is sometimes the only way to go, but it does not have to be expensive. Sometimes, off- the-rack drapes can be adapted easily with the help of a seamstress or your own sewing talents. There are plenty of good, off-the-rack options; you just need to think outside of the box. Add some trim, on the leading edge of the panel, or top or bottom, to add length, width, or interest.
Shutters are usually an added bonus, adding value when selling your home. However, they are expensive and view limiting. To take advantage of the view, you will want to have the widest possible louvers, or open the shutters during certain times of the day; but you will have to make sure the blinds will not interfere your furnishings.
Always, think of how you will use the room and its location before investing in expensive window treatments. Sometimes the easiest solution is the best. Consider a room divider screen as a window treatment, allowing ventilation; the design options are unlimited.