I think it is pretty clear that Peter was speaking against an oppulent show of wealth which is often used to put those who are not as wealthy "in their place".
He wasn't against braiding hair; he was against braiding the hair with gold and silver thread as was the custom of the time. Only the wealthy had the money, time, and labor (often slave labor) to do those intricate do's.
He wasn't against women wearing dresses, but he might have a problem with a $20,000 wedding dress, or designer fashion. Maybe even buying clothes for the label.
Whatever you do, wear, say, etc., you should always examine your motives behind them.
Here's my $.02- if you care to know what I think:
Peter basically meant that your inner beauty is more important than your outer beauty. He didn't legalistically mean you can't wear makeup and braid your hair, but that being preoccupied with outward appearance is unwise, if we neglect the true potential for beauty within.
That legalistic translation just devalues the spiritual content of the verse, lowering the standard to a carnal meaning, and putting the emphasis 180 degrees from the point of the verse in the first place.