Like in any other business relationship such values as respect, understanding, honesty and fair treatment should also apply to the translation business.
Both client and translator are experts who want to work together professionally and therefore, it is absolutely important to maintain a friendly and productive working atmosphere in which the translator always has the client and their interests in mind.
Communication is a very essential key, too. Therefore, please always inform your translator about such important information like, for instance, what the purpose of your translation is or which target group you want to reach.
Moreover, you, as the client, should not be offended if the translator gets backs to you if problems with translating certain terms arise. Quite contrary, you should be more than happy to answer those specific questions as this shows you that the translator cares indeed and wants to deliver the best translation especially appropriate to your needs.
This basically means that if the translator knows exactly what is expected from them, they will definitely go the extra mile and provide you with that extra bit of service to make the overall translation process as effortless as possible.
In short, the perfect business relationship is one in which both business partners treat each other the way they wish to be treated themselves.