Cover shoulders and knees at minimum in public; looser, non-revealing clothing is the safer default for both men and women, particularly outside international hotels and tourist zones. Women aren’t required to wear an abaya as a visitor today, but many still choose loose, modest layers, and it’s worth having one on hand for more traditional or religious settings.
When meeting someone of the opposite gender, don’t extend your hand first, the standard rule is to let the woman decide whether to offer hers. A nod, a hand over the heart, or a verbal greeting works as the default, and you can shake hands if she offers first.