It can be really tough packing for a trip to a conservative country. Some of the rules and traditions make it almost impossible to look cute and stay cool in the heat that is typical to these areas.
I always respect local cultural and religious beliefs when traveling because it’s what you should do as a good traveler. But it allows you to blend in better and helps you avoid unwanted attention. (Although not always, read my post on sexual assault in Morocco.)
Typically, countries that have a predominate proportion of their population practicing Muslim, Hindu and/or Buddhist religions are the ones that you’ll need to dress more conservatively in.
Rule of thumb when dressing for a conservative country: Knees and shoulders should always be covered — but in some places you may need to go as far as covering your hair, arms, full legs or feet. Watch that cleavage, ladies.