You can customize your meter readings using the spot metering on the camera to read values on the usual shadow areas of subjects you shoot, i.e: Landscapes usually expose for the landscape and not the sy, the sky can throw off the meter.
While calibrating avoid white surfaces, its better to meter on brick walls or alike or surfaces that are not glossy. Use different setting of reciprocity to test whether the meter is working correctly, i.e: f4@1/60. f8@1/30.... etc for 1 low light situation, one medium and high (related to the min and max of your meter [my yashica tlr goes as low as f3.5@1/30 but my minolta slr can go down to f1.7@1/30] ).

Further testing can be done by making sure the components are working correctly using a volt/amp meter, i.e: Resistors have to be in the right range, photocells/cds/photo-resistors can go bad and give ~0.1 ohms readings on both light and darkness, ussually its around 4-10kohms o light and +1mohs on darkness.
You can also use 3v batteries or combinations of them to make the meter more sensitive to light, and change the resistances accordingly to calibrate (a variable resistor or potentiometer works best for this.) ussually there are various variable resistors in the camera, turn them with a flat screwdriver or scissors and see the needle move as current passes through it.

Good luck!