When I first started traveling I would bring back gifts for everybody: my family, friends, co-workers, neighbors. Very quickly I soon realized I wasn't getting that many gifts back in return! (Yes, it's better to give than receive, but everybody likes to receive every now and then!) So IF you decide to buy gifts, only buy for a select group of people. The guy at work that you barely talk to isn't going to be jealous when he sees you giving a souvenir to someone else.
Make sure you have enough room in your bag to carry what you purchased back home. Recently a friend of mine was bringing me something I requested back from Canada. Upon weighing his bag at the airport, he realized that the bag was overweight. What got discarded?? My gift!! Try to buy things that don't take up too much space and are not too heavy.
traditional of the area. Buy something that you or your friend might actually use or need. Unless you have lots of room at home, don't buy a lot of junk for yourself. It will only end up collecting dust and eventually you might give or throw it away.