Spell it out carefully and consider what aspects of your description could be misinterpreted, then describe them in a way that won't be misinterpreted. Accuracy in describing what you want is your responsibility. Imprinting mistakes that result from inaccurate or inadequate descriptions by the customer will be at the customer's expense. Remember also that you must not expect absolute perfection in a custom made item that is produced in this manner. We will give you a great looking mug or other item but will not be sympathetic after the fact to your assertion that a color is a little off from your expectation or an arrangement of graphics is a bit different than what you had in mind.
Perfection is a difficult concept.
The eye of the beholder and all that. If your order goes through modifications as we exchange correspondence about it, we advise you to assemble all the changes into a final order and submit that to us as your final ordering step. If we exchange, say, a half dozen messages about your order and subsequently overlook an instruction contained in only one of those messages, we will consider only your final order submission in evaluating whether we have accurately executed your instructions. Please don't misunderstand. If we make a mistake we will take responsibility for it and insure that you ultimately receive items properly imprinted according to the instructions which you gave in your final order submission and to which we agreed.