I admit, I usually overpack when I'm planning what to wear for a trip...I mean, it's good to have options, right? That said, I have a few things I always do when I'm packing to help streamline the process and also keep my favorite clothes and accessories safe.
A week before any trip, I put out a clothing rail (the collapsible chrome ones with wheels) and start adding things to it in between meetings and when I have time. This way, I think of what to bring over a few days - instead of packing all at once the night before.
When I pack my suitcase, I always use soft duster bags to wrap my heels and handbags. For clothing, I like to pack most things on slim velvet hangers, wrapped in clear dry cleaner bags to help protect embellished dresses so sequins won't snag on sweaters and leather won't get scratched. Also, these bags can be reused over and over, they don't take up space in your suitcase the way some garment bags do and they prevent wrinkles for most fabrics.
Last, and I've learned this the hard way...If a bag feels super heavy, I'll pack an extra suitcase. Better to err on the side of caution so you're not tearing apart your suitcase looking for something to take out at the check-in desk lol!