It usually goes like this:
1. Hey my friend, where are you from? — So that he can set an initial price for you. None of the items ever have prices on them because of this. If say you're from Russia or Germany and the like you'll get the big initial price, if you're from Serbia like me, you'll probably get a smile.
2. Let's say you are from Germany, and were looking at a shirt, he'll tell you €40. — You simply can't allow yourself to buy it at this price, neither is he expecting you to (although I'm sure that happens). At this point he just wants you to pile up the stuff you like from the store.
3. When you're done, he'll sit you down for "the deal". Now's the time to haggle, and you should have been thinking of ways to cut the price while you were picking up the clothes. He'll probably give you a small discount "for bulk" that you should dismiss at once, and aim for at least 30% off of everything (50% is standard somewhere, some parts is less), and don't be afraid to return some things you don't want to buy.
So yeah, if you want some schooling in direct sales, go to Turkey (Alanya is very nice) and go shopping. Be prepared to come back with many knock–off Armani shirts and sweaters.
But the thing is that these people need the high margin sales to make a living. They'll sell at the lowest price that they're still making money, but if all of their sales are like that they're not making a living. That's why you shouldn't haggle all the way down if you like the vendor.