Absolutely! A journey to Istanbul, Amasya, and Trabzon is a wonderful opportunity to discover the rich culture and history of Turkey. Here are some travel tips for you:

Best Time to Visit:
Istanbul: It is best to visit Istanbul in the spring (April to June) and autumn (September to November) as the weather is mild.
Amasya: The months of May, June, and September are appreciated for their pleasant climate.
Trabzon: The best time to visit Trabzon is from June to September when the weather is pleasantly warm.

Route and Accessibility:
Istanbul: It's one of the main gateways to Turkey and can be easily reached by air, sea, and roads from numerous destinations around the world.
Amasya: From Istanbul, you can reach Amasya by taking a domestic flight to Merzifon Airport, then a taxi to Amasya. Another option is a train or a long bus ride.
Trabzon: The city can be reached by a domestic flight from Istanbul, or you can take a scenic bus ride.

Altitude and Acclimatization:
The altitude of these cities is not very high (Istanbul is 39m, Amasya is 412m, Trabzon is 37m above the sea level), so you won't have issues with acclimatization. However, it's always important to stay hydrated, especially in the hot summer months.

Accommodation and Booking:
Due to the popularity of these destinations, it's advisable to book your accommodations well in advance. There are many choices, ranging from budget guesthouses to luxurious hotels.

Clothing and Essentials:
Pack lightweight and breathable clothing for the summer, but also include a light jacket for cooler nights. For spring and autumn, layering is recommended. Comfortable walking shoes, sunscreen, and a hat for sun protection are essential.

Health and Safety:
Carry basic medicines and remember to get a health insurance package that covers your trip to Turkey. Be cautious of your belongings and pay attention to local advisories and warnings.

Local Etiquette and Respect:
Turkish people are incredibly hospitable, and when visiting religious sites, it's important to dress modestly. Also, it's a common practice to remove shoes when entering mosques. Try to learn a few basic Turkish phrases as this can greatly enhance your interactions with locals.