Well, the obvious goal is to match the spectral response of the film and the meter. In simplest terms, that means you could calibrate your meter by metering off specific colours and doing step-wedge exposures and seeing what EI for what colour gives the best exposure. Newer matrix-type SLR metering systems are colour-aware, and therefore do the compensation for you, as do the more advanced studio light meters. If as you say your negatives are perpetually badly exposed, I can only suggest that you consider more sophisticated equipment or do a series of tests with what you have and compensate accordingly. Last but not least, bracket whenever practical to do so.