Sacks should be sewn. Kitbags and barrels should be locked. A good porter will welcome this rather than resent it - it puts him beyond suspicion should something appear to be missing. Have sufficient food and all other requirements for the approach walk packed in a small number of loads for easy access. The majority of loads can be left intact till base camp.
Porters are surprisingly sensitive to small amounts of excess.
All that is possible should be done to care for employee's health as necessary. On the other hand they often show hypochondriac tendencies and undue faith in western medicine. Some of their complaints can and should be treated. Problems arise when the complaint is non-existent or beyond the party's resources to treat. A decision then has to be taken between the more honest policy of refusing to offer treatment and the more diplomatic one of giving a palliative.