Dress
The traditional dress of the Dominican Republic is heavily based on Spanish clothing, but also has influences from Africa. The Tiano people generally wore nothing prior to Spanish arrival (other than perhaps a loin cloth or a shirt called a nagua). With the Spanish arrival the dress shifted to dresses for women and shirts and pants for men. The dresses were Spanish-styled long free-flowing dress, often times with short sleeves and numerous colors and patterns on them. For men the pants and shirts were simpler and a hat was a common accessory.
Today the traditional dress of the Dominican Republic is still worn on some special occasions or holidays, but few people wear it on a regular basis. More common today is modern western-styled clothing, which varies based on personal preference more than anything else. However, the people tend to dress on the conservative side, especially in cities and inland; although conservative, the dress tends to be rather loose-fitting so it is a bit cooler.
As a visitor to Dominican Republic try to dress for the occasion as private resorts are filled with swimsuit-clad foreigners, but in the cities, and in particular in churches, the dress is much more formal and conservative. There are no issues with wearing shorts of short-sleeved shirts in Dominican Republic, but don't wear anything too revealing or short and try to avoid these clothes in more formal settings. Lastly, sunbathing naked or women sunbathing topless is often restricted so check with locals before doing so.