Turkey is a modern country without any restrictions about clothing for men and women. Sometimes people are concerned if they should obey some rules because of its muslim population. However country is secular, provides freedom of clothes to citizens as well as visitors.
When you are going to travel around Turkey, maybe if you follow these suggestions it might be more convenient for you.
In Istanbul if you stay close to Old city you can dress up as you like. Only there are restrictions when you go to visit mosque. Legs and arms are supposed to be covered for men and women and for women also hair should be covered with a scarf. If you don’t have scarf or clothes to cover yourself, they provide you at the entrance of the mosque.
If you are visiting the country side of Turkey, maybe it would be more convenient for you to wear bermudas, skirts at knee, and t-shirts. Also during the summer time you get to protect your shoulders with t-shirts instead of sleeveless tops. A scarf at your bag will always help.
Even in the most touristic areas, it is good to wear comfortable shoes to prevent any kind of injuries due to non flat surface.