in one's Sunday best
in one's best clothes that you would wear to go to worship in a church (in the days when people dressed in a more formal way to attend church)
I was dressed in my Sunday best when I went for the job interview.
How to Clean Jewelry
Blot dry with a soft cloth
Then, let the jewelry sit out on a towel to air dry completely before wearing it again. If your jewelry is still wet, wearing it can trap moisture against your skin, leading to minor skin irritation.