So, if you comb the hair with a little mist of water around the frame of your face, hold the hair down so you can see the straight line. Cut with the first pair around the frame of your face about 1/2 an inch or so. Then, take the thinning scissors (if your hair happens to be thick) and thin it out a bit. Take care to thin towards the ends of the strands of hair rather than towards the scalp. This will keep the main shape of the haircut for the most part but it will feel lighter and look better until you get into see the hairdresser or barber and give you a couple of weeks reprieve. If you get a haircut once every 6 weeks, that's 8.6 haircuts a year. If your haircut is around, say, $15.00 (which I do not pay BTW, tips on that later, but I think $15.00 is about average) you will pay about $130.00 a year on haircuts (for one person). If you stretched every haircut an extra 2 weeks that would change to 6.5 haircuts a year for $97.50 for a savings of $32.50 a year. If you did this 6.5 times a year, you would be getting paid $5.00 per time you stretched a haircut. It takes about 15 minutes to stretch a haircut (at the most 1/2 hour). That equates to $20.00 an hour for your time, or at the least, $10.00 an hour, plus the gas and time you saved by not getting your haircut. Multiply $32.50 by everyone in your family that gets a haircut and that's how much you can save per year.
Revision: Apparently I was too cheap. Here are some US averages for haircuts: http://www.usnews.com/.../28/what-america-pays-for-a-haircut
Happy Savings!