My biggest mistake as a female technician was excepting to train a male. Its a man ego thing. But what can I say, I was one of the best they had on the field.

Dilime your machines monthy or at least every 2 months the most. That is very important. Customers need their coffee. You wouldn't get service calls every day. I had no service calls but 1 every 3-4 months all because I took my time to delime every machine I was responsible of.