The best choice is the train. Go to Shanghai first, change trains at Jiashan or Jiaxing, and then change to local long-distance buses (many). There are also long-distance buses in Shanghai and Hangzhou, or go to Jiashan or Jiaxing.
You can go to Jiaxing first and then to Xitang. There are mainly ancient towns.
There are many ancient towns in the south of the Yangtze River, such as Wuzhen (former residence of Mao Dun), Tongli (former residence of Ye Shengtao), Jiaxing (former residence of Yi Dahong, former residence of Jin Yong) and Shaoxing (former residence of Lu Xun and former residence of Zhou Enlai). The distance between them is only 100KM, and many of them are an hour's drive. So, over there, if you have time, have a good stroll and take your time.
Among them, Wuzhen and Xitang are also my deepest impressions. These two ancient towns are not far from Jiaxing (within 2 hours' drive). If you have enough time, you can have a look.
The route should be Shanghai (Hangzhou, Suzhou)-Tongxiang (Wuzhen)-Jiaxing-Xitang (Jiashan).
To Wuzhen (hometown is Tongxiang), the best choice is a long-distance bus, which can be reached in about two hours. The public transportation there is very developed. Unless absolutely necessary, it is recommended to take a business car, which is cheap and fast. Long-distance buses between different places are basically a few or even a dozen times a day, which is more than expected and easy to sit. Taxi or black car can also be chosen, but the price is high, and it can be considered when there is no public transportation at night. Trains are the cheapest, but there are few trains. You can consider going to the railway station to see if there is a suitable one before taking a long-distance bus. When there is no direct coach, go to a bigger place nearby and change trains first. For example, if there is no bus to Xitang (Tongxiang) or Wuzhen (Jiashan), go to Jiaxing first, and there may be a local on-call bus. The folk customs there are good. I asked the way dozens of times, but I didn't meet anyone who pointed the wrong way.
The ancient town suggests living in folk houses. If it is not a holiday, a room is less than 100 yuan. Live in the ancient town of Tang Xi at night. Very good. House, boat, house near the river, carved big bed, 100 yuan per room. The conditions are also good. The night view of Xitang has some characteristics. At night, the lanterns on the river hang high and the atmosphere is very ambiguous. Ha ha laugh
Besides fermented grains, wonton and fried stinky tofu, there are many delicious foods. The best restaurant in Xitang is Qiantang Family. Fish and ducks are very delicious. It is said that you can't go to the branch. You must go to the one on the second floor of the riverside bridge. Yellow rice wine should be tasted.
Other mutton, such as Wuzhen, is said to be good. Anyway, every town has its own local characteristics to taste.
Zhouzhuang is closest to Shanghai, and there are many cars. It's also very commercial and doesn't mean much. If you must go to Zhouzhuang, there are many cars in Shanghai.
General route arrangement suggestion:
I wonder if there is a through train from Fuzhou to Jiaxing. If not, go to Hangzhou, then transfer to a train or coach, 100 km to Tongxiang (Wuzhen). You can stay in Wuzhen for one or two nights, and then take a long-distance bus to Jiaxing to see Yanyulou and Nanhu Lake. You can live or not, depending on your interest. Then go to Xitang (or Zhouzhuang) in Jiaxing and stay in Xitang for one or two nights. Then go to Jiashan and go to Shanghai by train or coach.