High gloss ceiling (if there is no texture), low slung furniture, no ceiling fans and window treatments mounted high as they can go.

In addition to all the great suggestions above, if your style would support this look, wide vertical paint stripes, tone on tone with two different paint finishes (matte and eggshell) could help as well, but this would look best in a traditional or transitional room.

What style are you? Traditional or Modern? Do you have colors you've committed to? What furniture, if any do you have?

I would go for semi-gloss ceiling colour in a light (not necessarily white) color. High gloss works, but it's hard to pull off in anything but a contemporary space.

Pick your colors carefully. Start with one colour and instead of going down the paint sample, try half or quarter tones to compliment the walls, ceiling and trim. Avoid kitch techniques that will date your home, especially if you don't anticipate a remodel in 5-10 years, or will need to sell it.

Put formal drapes at the windows, but hang the rod as close to the ceiling as you can, and have them hemmed right at the floor. Again, keep with the simple color palette.

Accessorize with your pop of color. Throws, glass, art on the wall. What you leave out, makes what you leave in stand taller. In this case, the desired result of your room is to make it :feel: taller.

Get furniture that is compact and low to the floor and keep it to the absolute necessary items. Less, especially in this case, will be more. (as in space, not just vertically)

This photo is from Metropolitan Home, and is a room decorated by Lori Graham.

Hang curtains as high as possible to the crown moulding, if you have it. Consider painting the ceiling a sky blue color, this will give a slight lift to the room. Use crisp white on the walls with at least one large mirror in the room. Hope that helps.
Charmean Neithart

We had the same problem ceilings that seemed very low - I used Simply Tan (I love this color - it goes with everything and everyone always asks me what color it is) at 100% on the walls and the same color on the ceiling at 25%. Both in semi gloss - this reflects the light and makes the ceilings much taller looking.