Let's just say that the hairdresser/wigmaster in your entourage is nowhere to be found. The following is my description, in layperson's language, of how to wrestle those pesky faux tresses into place. Included is material I previously wrote for Yahoo! Answers (and which the asker chose as the best!).
Divide your hair into little sections and pincurl them to your head (using two bobby pins). Alternately, you can divide your hair into several sections and wrap it around your head (close to the scalp), pinning it securely into place until it is all tightly against your head.
Then take a wig cap (it looks like pantyhose without the legs). Find your hairline just above the center of your forehead and using large U-hairpins (you can get these at a beauty supply store if you can't find them at your local drugstore), stretch open the wig cap and pin the hem of it to your hair at the center point of your hairline, working the pin into the hair that is pinned to your head.
Do this again to the left and right of the center pin, until the front is secure.
Then stretch the wig cap over the rest of your head as far as it will go, covering ALL of your hair. Pin it into place with five or six pins, all throughout the top, back and sides of your hair.
Now do the same with your wig.
The wig cap compresses your hair and makes it easier for the wig to fit; plus, it gives you something to stick your wig pins into. Keep sticking pins in until it feels secure.
Wilson, J. (2011) "Yahoo Answers: Ways To Fit a Snow White Wig On (Reply)," Yahoo Answers. November 2011. Retrieved from http://answers.yahoo.com/question/index;_ylt=AsscOzAyo4p_mxFNYfRwqaIMxgt.;_ylv=3?qid=20111111143240AApR1nO&link=mailto on February 13, 2012.