The quality of the question depends on sincerity and clarity, and you may be the only judge of both. The I Ching isn't particulary structured to answer questions that require a straight yes or no, so interpretation of such a question might prove difficult. In other words, 'How should I handle this problem?' is better than 'Should I handle this problem in such and such a way?'.
If your question is about a particular person, make clear which point of view you want. If you want to know how to act with regard to him or her, you yourself will be the subject appearing in the answer. If you want to know what this person thinks about you, or feels for you, make him or her the subject, and the I will take this point of view.
Two factors determine the outcome of a divination: the quality of the question and the quality of the interpretation. Learning to interpret the outcome of a divination depends on study and practice. There's no shortcut. Beginners not only face the difficulties of interpreting the symbolism, but at the same time those of interpreting the connexion. Users who are already familiar with the I Ching will have less trouble in this respect.
Familiarity with the Ta Chuan and the Shuo Kua certainly helps to provide a better context.