If you have difficulty making eye contact with people when you're speaking to them, practice it over and over again until it becomes natural. This was tough for me at first; I had to practice a lot. I tended to start the conversation making eye contact but then dropping my gaze, looking away, or glancing over the shoulder of the person I was speaking to.

Eye contact is a powerful thing, especially if you're trying to be persuasive. And persuasion is an important part of business, even if you're not in sales and even if you're a software developer.