Certainly! Guilin, Yangshuo, and Zhangjiajie offer breathtaking landscapes and unique cultural experiences. Here are some travel tips to make your journey untroubled:

Best Time to Visit:
The optimal time to visit these places is in spring (March to May) or autumn (September to November) as the temperature is moderate and the scenery is at its best. Avoid the national holidays as these attractions might be overcrowded.

Route and Accessibility:
You can access Guilin and Yangshuo easily by high-speed trains and flights from major cities in China. For Zhangjiajie, it's advisable to fly from major cities or take a train from Changsha. If you're going from Guilin/Yangshuo to Zhangjiajie, take a train or flight to Changsha and then another train to Zhangjiajie.

Altitude and Acclimatization:
Though these locations are not at high altitude, you still need to take it easy if you plan to do any hiking to allow yourself to adjust to the strenuous physical activity.

Accommodation and Booking:
Book your hotel or hostel accommodations in advance, especially during the peak season. Guilin, Yangshuo, and Zhangjiajie all have a range of accommodations from homestays to upscale hotels.

Clothing and Essentials:
Pack lightweight clothing for the warmer months and heavier, layered clothes for the cooler times of the year also include rain gear as the weather in these areas can be unpredictable. Comfortable walking shoes are essential.

Health and Safety:
Consider travel insurance in case of any accidents and ensure to have some kind of internet access as you may need it for maps or translations. Keeping a small first aid kit with essentials could be helpful too. For any hiking, be sure to follow the paths and advice from local guides.

Local Etiquette and Respect:
China is a culturally rich country with special emphasis on societal norms and respect. Be patient in crowded places, respect personal space, and be courteous. While visiting religious sites or traditional heritage culture areas, be sure to ask permission before taking any photographs of locals or sacred rituals. Dress modestly when needed, and respect local customs and traditions.