How do you frame sentences to family without sounding robotic?

Growing up with Hungarian parents, I understand a lot of the informal language, but I feel like I sound like a textbook whenever I try to speak back to them. I find myself over-formalizing everything because I'm scared of getting the cases wrong in casual conversation. How can I start dropping the strict academic 'classroom' grammar for a more natural, conversational flow that sounds like how folks actually speak in Budapest?