Hello! It sounds like you're gearing up for an exciting trip to Austria exploring Vienna, Linz, and Graz. Here are some travel tips for your journey.

Best Time to Visit:
The best time to visit these Austrian cities is during the spring (April through June) or fall (September and October), when the weather is pleasantly mild. During these months, you'll enjoy the nature with full bloom or the beautiful colours of autumn respectively.

Route and Accessibility:
You may find direct flights to Vienna from many international destinations. Once in Austria, for travelling from Vienna to Linz and then to Graz you can utilise the efficient Austrian railway network or drive along the beautiful Austrian autobahns.

Accommodation and Booking:
All three cities offer a wide range of accommodation choices including luxury hotels, budget hotels, and vacation rental homes. Booking can easily be done via numerous online platforms like Booking.com or Airbnb. Make sure to book in advance, especially during peak seasons to secure the best options.

Clothing and Essentials:
Pack a variety of clothing to adapt to the shifting weather patterns. This would include comfortable walking shoes, rain gear (like a small umbrella or raincoat), layers for cool mornings and evenings, plus warmer, summer clothes for the day. Essentials would include travel documents, health insurance cards, any required medication, and European plug adaptors.

Health and Safety:
Austria is generally a safe country with a good healthcare system. However, it's always advisable to have travel insurance. Make sure you have the emergency numbers on hand and adhere to the local rules and regulations for a trouble-free visit.

Local Etiquette and Respect:
Austrians express formal greetings when meeting someone and respect punctuality. It is common to say 'Grüß Gott' (greet God) in formal situations or 'Servus' in casual ones. When eating out, tipping by rounding up to the nearest euro is customary.