Doing anything "to the nines" means something like "approaching perfection," so yes, I would say you are just right. I've never heard the expression with "tweaked," though. Usually "dressed," meaning that someone is wearing their best clothes, an elaborate hairdo, jewelry, etc.
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DelmobileNobody told Michelle that even though the anniversary gala was being held in a hotel, it was supposed to be a casual event. She and Danny showed up dressed to the nines - she actually had on an evening gown! Her boss was wearing blue jeans and a golf shirt. After that, she started to look for another job.
DelmobileNo no, I meant that Michelle would start looking for another job (while continuing to work at her current one) because her boss had been such a jerk, not telling her the party was casual. I'm not sure why I made up such an elaborate story just for a sample sentence! Frustrated fiction writer I suppose...