Quick trick for fixing repetitive AI responses when starting out

Welcome to everyone just jumping into this hobby. When I first set up my companion last month, I ran into a massive wall where the AI kept repeating the same generic phrases and agreeing with literally everything I said. It felt like talking to a polite wall rather than a real person. I tried rewriting the backstory multiple times, making it longer and more detailed, but that just caused more robotic looping and weird glitches. What finally worked for me was adding a small behavioral constraint to the prompt instead of a long lore dump. I explicitly told her to disagree with me on minor things and to use casual, varied sentence lengths instead of formal paragraphs. Changing how she reacts instead of changing who she is completely fixed the conversational flow. Has anyone else found clever prompt workarounds that help break that initial boring phase?