Hello! Your trip to the beautiful cities of Rouen, Amiens, Lille, and Arras in France sounds exciting. Here are some travel tips to help you plan better.

Best Time to Visit:
The best time to visit these cities in France is during the spring (April to June) and fall (September to November) when the weather is good. The summer months can get busy with tourists.

Route and Accessibility:
All these cities are well connected by the French National Rail service (SNCF). From Paris, you can easily take a train to these cities. Rouen is about an hour and 30 minutes, Amiens is around 2 hours, Lille is about 1 hour and Arras is 50 minutes away by train from Paris.

Accommodation and Booking:
Accommodations range from budget hostels to luxury hotels. Booking can be done online through various travel platforms like Booking.com and Airbnb. It's recommended to book in advance especially during the peak tourist seasons.

Clothing and Essentials:
Pack layers to accommodate the weather, which can vary. Comfortable shoes are a must as these cities are best explored on foot. Don't forget to pack a universal power adapter, toiletries, and travel documents.

Health and Safety:
European Health Insurance Card (EHIC) holders are entitled to free emergency medical treatment in France. It's relatively safe to travel in these cities but do take precautions against pickpockets in tourist areas.

Local Etiquette and Respect:
French people appreciate politeness so remember to greet with 'Bonjour' (Good day). Try to learn a few phrases in French. It's also customary to say 'Bon appétit' before eating.