Sure, I'd be happy to help you plan your trip to Turkey. Here are some travel tips for your journey to Istanbul, Antalya, Fethiye, and Bodrum.

Best Time to Visit:
The best time to visit these Turkish cities is from April to May and from September to mid-November. The weather is pleasant, not too hot, and the tourist crowds are smaller than in the summer months.

Route and Accessibility:
Arriving by plane is the most convenient way to reach Turkey. Istanbul Ataturk Airport is the largest airport in Turkey, with flights from around the world. From Istanbul, there are daily domestic flights to Antalya, Fethiye, and Bodrum. Public transportation, taxis, and rental cars are widely available for local travel.

Accommodation and Booking:
Accommodations range from luxury hotels to budget guesthouses. It's advisable to book in advance, especially in peak season. Sites like Booking.com, Airbnb, and local Turkish sites offer a wide range of options.

Clothing and Essentials:
Summer in these cities can be quite hot, so lightweight, breathable clothing is recommended. Don’t forget your swimsuit, beach towel, and sunblock for the beautiful Turkish beaches. During the cooler months, pack a coat, scarf, and other cool-weather gear.

Health and Safety:
Turkey is generally a safe destination, but usual travel precautions should be taken. Petty crimes like pickpocketing can occur, especially in touristy areas. As for health, tap water is not potable everywhere, so bottled water is recommended.

Local Etiquette and Respect:
Turkish people are known for their hospitality. Respect for the elderly is a cornerstone of Turkish culture. It's important to dress modestly, especially when visiting religious sites. Tipping is common in restaurants and for services.