If time permits, you can go to downtown Xiamen. Zhongshan Road, Gulangyu Island and Botanical Garden are all good choices.
On Jimei side, you can go to Mastiff's kennel (where the beach is clean and the environment is good) and Jiageng Park during the day to see the buildings of Jimei primary and secondary schools, which are very distinctive (designed by Chen Jiageng). The architecture of the Chinese Language Institute is also very beautiful. This is a school with a long history, especially at night. The night view of Longzhouchi is a major feature of Jimei, which is very beautiful. The Garden Expo Park is also good. There is a flower show recently, and there is a light show at night, which is very good.