Even if one of your coworkers isn't your most favorite person in the world, you should still show interest in their lives. Ask them how they are, learn what they like, dislike, and even a little about their family.
When working with others, it really helps when you can see things from their point of view at least a little bit. By understanding a little about who they are, you will be able to do this. If you know that Sally just got divorced, you're going to be able to find a bit of extra patience for her. If you know that Kai is hard of hearing in one ear, you'll make sure to speak a bit louder. Even something as simple as, Monica is NOT a morning person will help, as you know to schedule meetings with Monica in the afternoon whenever possible. If it has to be in the morning, bring some coffee to sweeten her up a bit;)