Cars are king, pedestrians are nothing, cyclists do not exist… so, as a pedestrian, you need to give way to cars and not expect them to give way to you.
Officially cars drive on the right, but you can never be sure! Look both ways all the time.
Zebra crossings are meaningless unless there’s a traffic light in place.
Even if there is a traffic light for pedestrians and you are crossing at green for you, still be cautious.
If you are crossing one way road, still check both of the directions.
Don’t forget that traffic is the biggest danger for you in Istanbul and Turkey!
The above are serious recommendations but take them with a light-heart! :)