Sure, I'd be delighted to provide you with travel tips for your visit to Vianden, Echternach, Clervaux, and Wiltz.

Best Time to Visit:
The best time to visit these Luxembourgish towns is from May to September when the climate is pleasant. However, if you enjoy winter sports, December to February could also be an interesting period to visit.

Route and Accessibility:
All the mentioned towns are accessible from Luxembourg City, the capital. Trains and buses operate regularly between these locations. It's worth renting a car if you want to explore the diverse landscapes at your own pace.

Accommodation and Booking:
There are numerous hotels and guest houses available for stay in these towns. It's advisable to book your accommodations in advance, particularly during peak travel season (May-September).

Clothing and Essentials:
Keep a mix of clothing suitable for different weather conditions as Luxembourg weather can be unpredictable. Don't forget your hiking shoes if you plan to explore the beautiful landscapes. Also, carry an umbrella or raincoat as rain showers occur frequently.

Health and Safety:
Ensure to have your routine vaccines before the journey. Luxembourg is generally safe but like any other travel destination, stay vigilant about your belongings.

Local Etiquette and Respect:
Luxembourg society values manners and a degree of formality. A firm handshake is the common form of greeting and mutual respect is expected. Also, maintain quiet in public places as locals value their peace and tranquility.