Regarded as one of the first shopping malls of the World, your itinerary in Istanbul should include a visit to the Grand Bazaar which is around 30,700 sq mts with over 60 streets and alleys and 4000 shops.
Realistically you won’t be able to cover all of Grand Bazaar in one afternoon because its opening hours are between 9:00 to 19:00 and it is closed on Sunday. So the whole point of the visit is to enter the Bazar move around check out shops, bargain, chat with some of the vendors and collect your souvenirs.
Visiting the Bazaar can also be daunting to some, as there is a tendency of some vendors becoming too aggressive in their intention to sell the product irrespective of whether you want to buy it or not. The best thing is to walk away from the vendor as there will be some who genuinely will be selling stuff you will really like without the unnecessary coercion.
The Bazaar has lots of things that you can buy, best would be to shortlist the things that you want and at what street they are available. Best buys are the turkish spices, creative different jewellery, their decorative lights or their famous designer carpets. The list is as per me, so you can have your own choices. Anyway till then some pics of the Bazaar from my end.