If you visit Turkey.......

Talking loudly on your phone on public transport is frowned upon.

Blowing your nose in public is not good manners and very shameful for Turkish people for example, you should go to the toilet to blow your nose.

When asking someone for a location ( when you are lost) Turkish people will be happy to help and may even change their direction to take you where you want to go. (Generally outside Istanbul most people will be do this, in Istanbul maybe a few :) !!)

Before starting a conversation you should say excuse me and during the conversation you should use formal language till getting closer.

Asking about money or age is not good behaviour.

You should visit Hagis Sophia, Blue Mosque and Basilica Cistern...

You should visit the old capital; Constantinople of Byzantine. İstanbul is a historical city.