If you're short on time, avoid places like Topkapi palace, etc. They charge yabancis (foreigners) out the nose, and the grand bazaar is cooler anyway... and has free admission. Give yourself a solid two days to fully explore it. Make sure to take a water taxi to Uskudar on the Asian side of the city!

Best place to stay in Istanbul -SulanAhmet (£25 to 40 per night). Low cost airlines go to Sabiha Gokcen Airport. Take Bus upto Taksem (cost 10 Turkish Liras). The journey is 45 mins to 75 minutes. From Taksem, take a taxi to Sultan Ahment. Better if you fix the rate before hand to 10 to 15 Turkish Liras. Places to visit: SultanAhmet mosque (blue mosque), Yerebatan Cistern, Top-Kapi Palace, museum opposite to SultanAhmet mosque if you realy interested in musuem. Istanbul Nightlife: Taksem. Turkish Hamam: Sultanahmet hamam at Sultanahmet. Approx cost Liras 60. The hama is not relaxing; you would need good sleep after you are massaged!

When you want the true Turkish experience and you want to stray off the beaten tourist path, find a hamam the Turks visit themselves. Once in there, go with the flow...observe those around you and don't shy out of a massage. It might look scary to have your bones racked like that, but it sure is a must-experience event.

Haggle....mentally put a price for yourself in advance: how much do I want to pay for it. The first bid you do should be ridiculously low...after all, the vendor's price is ridiculously high in the first place. He will set a new price...you now both know you're in for the game. Start haggling down and be overly dramatic about it...ask special discounts if you buy more than one item, make a total price. Threathen to walk away, you'll be called back with a new price...yet know that if you indeed walk away, don't come back for the same item. Because then the vendor knows you're interested. Let your travel partner/spouse play the bad cop, as if she/he doesn't want you to spend that much money on the items. The vendor will often his price to meet the spouses' criticism. Watch out what you say to one another...even in your own language. The vendors speak much more languages than you'd imagine. Stop when you're both happy on the price...and have fun.
That way both parties will be satisfied about the deal. There's no use in angering vendors by trying to press for ridiculously low prices.

If you are looking for an inexpensive and totally unique gift to buy for friends, get a prayer necklace: a small black leather triangle with a verse from the Koran stitched inside. The come hanging on a black leather strip that can be tiedd to turn the triangle into a choker necklace. I have received more comments and compliments on this simple piece than on pieces that cost a thousand times more. They usually can be had for about $1 (US) but sometimes you have to hunt or ask for it because not many people have caught on to it yet!

One of the best shopping deals in Istanbul, is the elastic waistband cotton pant. Buy them on the street. You will find several vendors down in the harbor where the tourboats leave from. Go down in the tunnels that allow you to avoid crossing the busy roads. I have found one vendor there who sold me pants for $5 a pair because I kept on bargaining and kept on adding to the number I was going to buy. Hey, the fold really flat and they make GREAT gifts. I ended up with 20 pair and he make a week's worth of sales in less than an hour.

Great restaurants/clubs in Istanbul:
Reina (http://www.reina.com.tr/) 360 (http://www.360istanbul.com/) Anjelique (http://www.istanbuldoors.com/en/)

Good food, great music, beautiful people, incredible view!
Check it out...

One marvellous little city ... marvellous because it has amazing sights, food, history, attractions and charm ... and little because much of this is conveniently concentrated in the old part of the city Sultanahmet ... you can get here straight from the airport or station .... the rest of the city is largely a modern sprawl that you will need only if you have private or official visits to make, or sample modern Istanbul, or connect to other cities, or go to see the few things outside (such as the touristy Bosphorus or that bridge, walking on which you cross from Europe to Asia) ... the main attractions otherwise are in easily walkable Sultanahment ... the Blue Mosque, Topkapi Palace, Aya Sophia ... these are certainly worth it ... but do take the time to sample some good Turkish food, get scrubbed and soaped and sprayed and beaten and by huge Turkish masseurs in a hammam, watch a Sufi dervish dance while smoking a sheesha, linger over cups of Turkish tea or coffee, ... these are the experiences that really stay ... be careful of the carpet sellers though as you navigate Sultanahmet (they can get quite persistent) ... plenty of hotels to choose from ...backpacker to mid-range to starred... so I don't see the need to book in advance except for peak season... walk around and take what you like instead (I've heard of a hotel 'Poem' that I intent to sample in the next visit, where rooms have poems instead of numbers to identify them...) ... Turkish sheeshas and tea-glasses make good tourist buys ... Istanbul is not just a major crossroad now but a major tourist spot too and you are bound to come across several faces of both the tourist industry and the tourist ...

you never need a tour guıde

As with any large city, be sure to keep an eye on your wallet, purse and luggage.