For students, you don't need to choose a particularly expensive gift, just a decent one will do. The hardest job for teachers is of course teaching, and the most important thing is to protect their throats. Tea is a good gift. If it's a female teacher, you can give herbal tea. There are also other benefits such as beauty, which can relieve stress and are good for the body.
There is also a small gift that can be attached. If you make it yourself, it will be more precious and meaningful. You can customize the gift on the website and use the photos of your classmates and teachers to make some commemorative gifts. Upload your photos and write some words to bless the teacher. It is creative and interesting. Since you are a student, it is not appropriate to give very expensive things. This kind of small gift designed by yourself is thoughtful and not expensive, which is quite good.
Gift recommendations: blessing chocolate (you can write your own blessing), name necklace (making a necklace with the name of the head teacher is also good), life-like doll (ceramic sculpture made of photos, interesting and meaningful).