Packing Take some summer clothes and what we used to call demi-saison (light-weight long pants, sweater, jacket) and a hat to wear in the sun. I took the next to last tour of the year and Cappadocia wasn't the only place that was chilly, though by mid-day, it was usually warm enough for short pants and sleeves. Bathing suits for Pamukkale. Good walking shoes and comfy sandals too. There was an option to have the hotel in Cappadocia do your laundry - line-dried on the roof. If you must have coffee in the morning, bring some instant with you. The hotel in Cappadocia did not serve it. It's easier to get a beer in Muslim Turkey than a cup of coffee. Tea is far and away the main beverage.
Side trip Definitely sign up for the balloon ride in Cappadocia. For almost everyone who does it, it's one of the real highlights of the trip. I don't like massages, but even the guys who went (dragged, I suspect, by their mates) had a good time. And non-smokers had fun at the "hookah experience" (which I also skipped). But before you choose to visit a Turkish barber, watch this
Must-dos I spent a few days in Istanbul with a friend before she left and I joined the tour. There's so much to see, I highly recommend as many days as you can before and after the tour. The tour spent very little time at the Spice Market and it was mostly with one vendor (he vacuum-sealed our purchases and mine made it home in excellent condition, both spices and sweets). You may want to go on your own (but not on Sunday - it's extremely crowded then). Taste the Turkish delight ("lokum"), it comes in lots of flavors, try them all, though maybe not all at one vendor. You can buy some, plus great dried fruits and nuts, for snacks during the tour. The stalls outside on the fringe of the market are just as good and considerably cheaper. The sights I most enjoyed outside the tour: Mosque of Suleiman, Cisterns, Archaeology Museum. The RS walks are good. My friend and I also enjoyed just walking and exploring, on both sides of the Galata Bridge, peeking into small mosques and myriad shops we passed.