Turkey is a low-slung dollar burner.
With the value of the Turkish lira always sliding, it's best to change money every few days. Keep an eye on all the zeros on your bills - it's easy to mistake a 500,000 lira note for a 50,000 lira note. Keep some exchange receipts as you may need them to change liras back at the end of your stay. In cheaper restaurants it's not necessary to leave more than a few coins in the change plate. In more expensive restaurants, tipping is customary.