I've learned a secret trick. Just get good at asking questions. And then really listening so that you can ask follow up questions. It can seem awkward and weird at first and sometimes the kids look at you all weird. But, kids like to talk about themselves. Asking them questions gives them a chance to talk about themselves and it gives you a chance to listen to show you care.
Having a skill, like asking questions, makes being interested in your kids a choice instead of a feeling. The caring is what you do, not that you have high regard for them. Even if you struggle with liking a kid, maybe especially if you struggle, it is important to remember that you can choose to do the caring. And I have found asking questions, sincere questions, about their life and their interests has been an almost certain way positive regard toward my students.