Turks do not generally have a very strong sense of space and the space between two people will vary, the furthest distance being the length of one’s outstretched arm with tips of the fingers touching the other person’s shoulder.
Regular eye contact, not necessarily sustained, is used in judging whether a person can be trusted. Although constant eye contact is not necessary, people will be suspicious of a person who refuses to or is reluctant to make eye contact.
It is customary to shake hands with both men and women when greeting the person. In some cases, men and women will give each other a kiss on each cheek. While talking, men and women could frequently touch each other, for emphasis. This rule is different if the woman in question is obviously highly religious, i.e. wears a head covering and is fully covered from head to toe. In this case there will be no cross-gender handshaking, unless initiated by the woman; just a polite tip of the head will suffice.
Friends are more likely to touch each other and throw their arms around each other as a regular impulse.
A neutral facial expression with an active (i.e. varying) tone of voice, rather than monotone is always appreciated until the relationship has matured.
The rudest hand gesture is the thumb through the index and middle fingers, and should always be avoided.