If you are stuck for ideas of what to buy him, look for things that he uses often, but may not want to buy himself. For example, if he has a bad habit of leaving his keys in the car when he goes out, surprise him with a nice keychain which will serve as a reminder to always put the keys in the car when he leaves. If you feel creative, why not make it a customized keychain with his initials on it! You can find a variety of cool keychains in different shapes and styles which you can personalize in any way you like. There are also DIY projects that let you turn old keychains into something unique.