If You Feel Too Small Your Room’s Too Tall!
One of the simplest and cheapest solutions is too add a darker shade of paint to the roof. Dark colors give the illusion of weight, and a heavy ceiling in turn gives the illusion of being closer to the ground. This may sound too simple to solve the problem, but the difference this simple step makes is quite phenomenal. Another solution is to add a horizontal line of wood, either plain, carved or patterned around the room. Adding this will divide the room into an upper and lower portion. The height at which you add this wood is up to you, however it is normally fixed at the top of the windows. If your windows are split into a couple of pieces, you might use one of the wooden window pane separators as your height.
Combining both of these techniques accentuates the above effects even more. By fixing a piece of horizontal trim around the room and then painting the top portion of the room with a darker color, you will create the illusion of a much lower ceiling than actually exists. This can work especially well when the two colors are quite different from each other. They don't necessarily need to be saturated colors (they can be a hue) however make sure that the colors do complement each other. All the normal rules of interior design still apply, and you don't want to solve the large room problem only to replace it with a disgusting color problem!
If the room you are having issues with is exceptionally tall and you don't think the above solutions will solve your problem, you might want to consider the more drastic step of dividing the room into two rooms. You can set the ceiling height or the lower room as you want it, and add the second level above this. This might be a bit of a loft or storage area and doesn't necessarily need to match the floor size of the lower lever. It might for example only protrude one or two meters from the far wall, displaying its content like a kind of over sized shelf. This will produce a similar illusion to the horizontal wooden trim only more pronounced.
So there are a couple of tips to fix that room that is just too tall for its own good. If this problem was preventing you from using this room then fixing it and reclaiming the space will make your house just that little more comfortable.