For a semi-formal occasion such as a party or dance, you'll want your hair to look dressier than your everyday look, but not as dressy as if you were going to a black-tie affair. Simple semi-formal hairstyles are easy to do yourself, and they look pretty but not overdone. For a semi-formal occasion, you can wear your hair up or down, depending on your preference and how long your hair is.
Wearing Hair Down
The most classic way to wear your hair down to a semi-formal event is to wear it in curls. To avoid looking too formal, try looser curls. To get the look, take a section of your hair, place it in a flat iron, and turn the iron, wrapping your hair around it as if it were a curling iron. If you want more curl, begin with the flat iron toward your roots. If you want less curl, begin with the flat iron in the middle of the section of hair, so that the hair on the crown of your head remains straight. Repeat the curling action, section by section, over all your hair, and then spray with a flexible-hold hairspray.
If you have a chin-length bob, it's appropriate to wear your hair down to semi-formal events. Simply clip in a decorative piece, such as a feather or flower, or wear a pretty headband that complements your outfit.
Wearing Hair Up
You can wear a simple ponytail during semi-formal occasions. Just pump up the volume to make it something special. Before tying the ponytail, take sections of hair from the crown of your head and back comb the roots (this is called teasing). This will create lots of volume on the top of your head. Spray the teased hair with hairspray to set it, and then tie your hair back into a ponytail. This look is also pretty with a headband in front of the teased hair.
A polished, dressed-up bun is just as easy to do. Run a flat iron over the roots of your hair so that the pulled-back part of your bun will be sleek and smooth. Secure your hair at the base of your neck, as if you were wearing a low ponytail. Take sections of the hair from your ponytail, wrap them back around toward your head, and clip them into place with a bobby pin all around the ponytail. This will make a uniform bun as well as hide the ponytail elastic. Spray lightly with hairspray, especially around the bobby pins, to hold. This look also works with a side ponytail.