For conservative industries, don't wear earrings. Observe other men in your industry to see what is acceptable. Women can wear casual pants or skirts. Neither should be tight. If you are pursuing a conservative industry and are in doubt, observe well dressed women in your industry on the job, at career fairs, at information sessions, etc.
Skirt lengths come and go.
Before choosing a skirt to wear, sit down in it facing a mirror. Ask yourself whether it will be distracting or reinforce your image as a person who looks appropriate for a business environment or gathering. In addition to tailored shirts or blouses, tailored knit sweaters and sweater sets are appropriate business casual choices for women. Jewelry and scarf styles come and go. Keep your choices simple and leaning toward conservative.