Look around the air ducts and see if the metal tape is pulling up. If it is put new on it clean the surface before applying the tape or it will not stick very well. Every bit of air that leaks out is conditioned air you lose.
While the pilot light is off is the time to service the furnace fan and vacuum out the burner areas.
If you are daring it is also a good time to do a couple of other things.
You can pull the furnace out of the way and clean the coils for the AC.
You can pull the blower out and clean the fan blades.
Check your blower motor to see if it has oil plugs and oil it if it does.