If you can't do the pressure test, waiting for a windy day works pretty good too. The leaks will be much more pronounced in windy weather.
The heat is a common issue. I just suggest turning it down whenever you can (night/out of the house). The common saying that it takes more energy to heat the house back up vs keeping it warm all day is completely wrong and actually defies the laws of physics.
As far as other suggestions, since you have forced air, I would really look into getting a roll of aluminum tape and sealing your air ducts as much as possible. This is a horrible source of heat loss in some homes. Tape is cheap too!
DAP seal'n'peel is a good product for old leaky windows. I plan on putting some of this on mine this fall yet.