Here we go...

In Istanbul, take a boat trip. We recommend 'vapur's. Probably the most economical way of getting all accross the Bosphorus in a few hours.

Never drink tab water in Istanbul.

Tipping 10% in restaurants is customary

Bring with you or buy upon arrival adaptor plugs for your electric appliances. Standard 2-pin plugs are used all around the country with the exception perhaps expensive, luxury hotels. Voltage is 220 with 50 hertz.

If you're buying a rug and you want to know if it's hand-made, check behind it; it should be uneven.

Traffic is hectic and heavy in Istanbul almost all the time. Leave in good time for appointments

If you're into drugs, be careful at this moment. It's said the best stuff is out there, but you're not in Amsterdam. Even a joint would most likely get you to a "joint".