Dress one or two levels above what you will be wearing daily on the job. If it’s jeans and flip-flops, go to nice business casual. If it’s business casual, move up to a suit.
Consider the organization’s culture. Youthful tech companies are much more casual than banks. Advertising agencies are much more fashion conscious than most government agencies.
If you will have external contacts, (clients, prospects, vendors, partners, etc.) dress to meet them, not just the employer.
Avoid perfume and aftershave. You don’t want to trigger your interviewer’s allergies.
Limit the jewelry, both men and women, unless it’s expected by the culture.
