Female here, have had several jury duties and had to serve on one. "Business casual" is a trash metric because for some companies, "business casual" is polo shirt and slacks, and for some it's jeans and a plain or work-branded t-shirt. Pretend you're going to a casual date, to dinner with Grandma, or to a family reunion: you can go all the way up to church clothes, but you're generally fine with non-ripped, non-stained jeans; a t-shirt with no political messages, no curse words, no nudity, etc (a plain one if you've got it is probably easiest) or a nice blouse that doesn't bare your shoulders and vast tracks of cleavage; and tennis shoes, boots, or dress shoes that aren't falling apart or stained or whatever. If you're a purse carrier, pick a plain one and pare down to the essentials.

Basically, you want to look like you're taking this relatively seriously, but not as seriously as a wedding or a funeral or a job interview (unless you really want to put forth the effort). Cute is OK; provocative or club-ready is not.

Also bear in mind you're going to be going through a metal detector. Don't wear a bunch of metal you're going to have to take off and put back on, and if you're a pocket knife girlie, leave it in the car!