Well, it's never going to look tall, but there are things you can do to help. Keep the colours light and make sure it's well lit. Emphasize vertical lines when you are planning the decor. Put full length drapes on the windows even if they're the little short ones at the ceiling line. Maybe even put a vertical stripe wallpaper on an accent wall. If you make bookshelves, divide them into vertical sections and make the vertical dividers more prominent. These will all help!

If you really meant 6'7" and not 7'6", then you need to check local building codes. A 6'7" ceiling does not qualify for habitable living space, such as a bedroom, and most municipalities won't give you a permit for anything other than storage space in that area. Design can only make it look pretty, not comfortable, unless your whole family is very short. If your budget allows you could dig out the space to create 8ft ceilings. It's successfully done all the time and is less expensive than adding on.

I agree with Parrish except that I would investigate the space between your ceiling and the floor above it to see if the ceiling can be raised or at least coffered between the joists. :)

Here are a couple of tricks I learned from HGTV:

Take your wall color and paint it on to your ceiling a few inches in. Fool the eye into thinking the walls continue! Taylor Luce sounds right to me, keep colors light. (A bright light carribean green helps my dark bedroom).

Paint the middle area of ceiling (portion not covered by the wall color) a pale sky blue.