First, you have to find out what he likes. Figure out what his hobbies are. For example if he likes playing Video Games, see if hes been interested in a new game thats coming out and get it for him. But one thing to make sure of, is to make sure you do not get him something he already has. If you can go through his room to make sure he doesnt have that game your about to put great thought into. That saves him time in having to return the game and go pick out another one. Some people cant make up thier mind and decide to get gift cards for places so they can go and buy what they want, but that is up to you if you would like to be more personable, and get something with meaning or not. Its up to you to figure out what he is into. Then get him something that he didnt expect! He will love it!