depends how much you want to spend

also depending on which cities you are in.

under 10 euro--you need to check out the rate, it changes from time to time.
1. 折扇--it has many different kinds. you make your choices
2. table cloth-it has many design.
3. post card-of course, alwasy, haha
4. and other small gifts that you can find at shop.

over 10 euro
wine-not easy to carry, but maybe good to your boss. ask local people, i forget the name.
chocalate--various.

these are all from my memories. you will find many when you are there. people are very nice there. but still need to carry your money and important things carefully.