Any service industry professional knows that the customer is always right. Some brides are a cinch to deal with, but others range from difficult to overwhelmingly high-maintenance. A good planner won't let on that your habits annoy her, unless you're being verbally abusive or otherwise disrespectful.
Avoid acquiring the unflattering Bridezilla moniker by using those basic manners your mother taught you and keeping your expectations in check. Remember that your planner -- no matter how experienced or expensive she might be -- isn't a mind-reader and can't be expected to act like one. It also stands to reason that the better you treat her, the more effort and care she'll put into preparations for your big day. Make an effort to play nice, even when you're stressed out and inclined to take it out on her.