Hello! That sounds like an exciting trip. Here are some travel tips for your visit to Guilin, Yangshuo, and Zhangjiajie in China.

Best Time to Visit:
The best time to visit these places in China is from April to October when the weather is pleasant, less rainfall and the scenery is at its best. Try to avoid Chinese national holidays when these places can be extremely crowded.

Route and Accessibility:
You can start your journey from Guilin, which is accessible via air from major Chinese cities or even directly from several international countries. From Guilin, you can take a river cruise to Yangshuo. Travel to Zhangjiajie can be done via a domestic flight from Guilin or a bullet train from Changsha.

Accommodation and Booking:
You'll find a range of accommodations in these cities, from budget hostels to luxury hotels. It's recommended to book your accommodations in advance, especially during the peak travel season. Many hotels offer online booking services.

Clothing and Essentials:
Carry comfortable walking shoes as these locations involve a lot of hiking and exploring. Dress in layers to adapt to the changeable weather. Don't forget to bring your camera, sunscreen, and a hat or umbrella for protection against sun or rain.

Health and Safety:
While these areas are generally safe, always be aware of your surroundings, especially in crowded tourist spots. Stick to bottled water and eat at reputable places to avoid food-related illnesses.

Local Etiquette and Respect:
In China, a respectful attitude towards locals and their customs is appreciated. Observe rules at religious and historical sites. It's also recommended to learn a few basic phrases in Mandarin, as English is not widely spoken in the more rural areas.