Hello! That sounds like an exciting trip! Here are some travel tips for your visit to Istanbul, Amasya, and Trabzon in Turkey.

Best Time to Visit:
The best time to visit Istanbul and Amasya is during spring (April to June) and autumn (September to November) when the weather is mild and pleasant. While Trabzon, located near the Black Sea region, is best visited from June to August when it's relatively warm with less precipitation.

Route and Accessibility:
Istanbul has two international airports and is well connected to major cities worldwide. From Istanbul, you can reach Amasya by bus, train, or flight to Merzifon Airport which is close to Amasya. From Amasya, you can take a bus to Trabzon. Trabzon also has its own airport that provides domestic connections.

Accommodation and Booking:
All three cities have a wide range of accommodation options from luxury hotels to budget-friendly hostels. It is advisable to book your accommodation in advance, especially during the peak tourist season, through reliable booking platforms.

Clothing and Essentials:
Pack a mix of light and warm clothing as weather can still be unpredictable, especially in Trabzon. Always carry a rain jacket. For visiting religious sites in Istanbul, modest clothing is required. Don't forget your sunscreen, sunglasses, hat and comfortable footwear for exploration.

Health and Safety:
You should definitely have travel insurance covering health. Turkey is generally safe but like anywhere, take care of your belongings and avoid less crowded places at night. Follow any local COVID-19 guidelines and ensure your vaccinations are up to date.

Local Etiquette and Respect:
Turks are generally warm and welcoming. Respect local traditions and customs. Modest clothing is recommended, especially in religious places. Removing shoes when visiting someone's home and tipping for services rendered is part of the culture.