A 10%–15% charge may be added to the bill in restaurants (look for it under the label servis). In top establishments, waiters expect tips of 10%–15% in addition to the service charge. Although it's acceptable to include the tip with your credit card payment, cash is much appreciated.
In Turkey, taxi drivers are becoming used to foreigners giving them something; round off the fare to the nearest 50 kuruş. Dolmuş drivers do not get tipped. Hotel porters expect about 2 TL. At Turkish baths, staff members who attend to you expect to share a tip of 30%–35% of the bill: don't worry about missing them—they'll be lined up expectantly on your departure.
Tour guides often expect a tip. Offer as much or (as little) as you feel the person deserves, usually 10 TL to 20 TL per day if you were happy with the guide. If you've been with the guide for a number of days, tip more. Crews on chartered boats also expect tips.
Restroom attendants will not expect a tip in addition to the charge for using their facilities.