Soula Centre
Just outside the souk has fixed prices, it is useful to establish values before bargaining in the souk of course there is no fun.
Medina
Including the souk located in the center of the city. the old section of the city containing the local bazaar, expect to haggle or barter.
Everything is pretty cheap, but merchants won't hesitate to quote outrageous prices, so haggling is necessary. Take it all light-heartedly though and have fun whilst haggling. Obviously, there is a large quantity of counterfeit designer goods available in the Medina.
Don't waste your and their time if you don't intend to buy anything and if you are only interested in taking a look, make it clear from the beginning. Say nicely and with a smile that you are not interested or that you don't have any money left. However don't feel obliged to buy if you can't agree a price.
Don't keep thinking about the price after you buy something. Think on the good deal that you have made and the price that you would've paid in your home country.
Don't expect to have language issues as merchants speak almost anything common French, English, Spanish, German... - you can mix all languages if you want.