"A passage should be interpreted according to how the reader of the day would have understood the words."

Most theologians would offer such hermeneutic as a guideline rather than an absolute.  For example, there were many prophecies that appeared to have a "minor fulfillment" in an earlier day, and a "greater fulfillment" in Christ.  To apply the above hermeneutic without any control would eliminate such dual prophetic sayings.  For this reason, methodological assertions are best developed in a slow, retroductive method, just as substantive assertions.

Another example would be:

"If there are two interpretations to a passage, on natural, and one supernatural, you should prefer the natural." 

This methodology was illustrated in the context of Jesus directing His disciples to the man with the pitcher of water on the eve of the passover.  One might imagine an expositor offering this heremeneutic as a corrective to a series of outrageous interpretations of Scripture, where mundane events are given outrageous miraculous interpretations.

All of us have presuppositions, both substantive and methodological.  This is not wrong.  But it is helpful to be aware of them when interpreting scripture.  The errant conclusions drawn from one passage become substantive presuppositions for interpreting the next passage.  Without an awareness of the theological framework and hermeneutical presuppositions on which we rely, we can rapidly drift far afield of sound Bible doctrine.