Hello, it sounds like a fantastic trip to Austria's most charming cities you've planned! I'm here to assist you with useful travel tips.

Best Time to Visit:
The ideal time to visit Austria may vary depending on your preferences. For city tours, summer (June to August) offers the best weather conditions, though it is the peak tourist season. Spring (April to June) and fall (September to October) offer mild weather, less crowd and beautiful landscape, making an equally good time for visiting.

Route and Accessibility:
Flights to Vienna are the most convenient choice for international travel. From Vienna, domestic trains operated by OBB provide comfortable and efficient connections to Salzburg, Graz, Klagenfurt, and Innsbruck. Renting a car is another suitable option if you prefer a leisurely drive.

Accommodation and Booking:
Austria offers a range of accommodations, from luxury hotels to budget hostels, and holiday apartments. I recommend using reputable booking platforms to secure your stay in advance. Remember, peak seasons may make bookings challenging, hence it's best to reserve in advance.

Clothing and Essentials:
In the summer, pack lighter clothing with a few layers for cooler evenings. In the spring, fall, and winter, warmer clothing is recommended. Always have an umbrella or raincoat for unpredictable showers. Don't forget your hiking equipment if you plan to explore the Alps.

Health and Safety:
Austria is considerably safe, but it's wise to have comprehensive travel insurance for unforeseen circumstances. Always stay hydrated, especially during hot summers or if partaking in physical activity like hiking in the mountains. Lastly, make sure you're up-to-date with routine vaccines before traveling.

Local Etiquette and Respect:
Austrians place high value on privacy and politeness, so try to respect these cultural traits. Tipping is customary in restaurants and for services. Learning few phrases in German can be helpful as it is the local language.