Hello, I agree whith my colleague. You need practice and exposure to the language.But if you want a quick help, you can add a "t" before the word. For exaple, if you want to say "rápido" you can start saying "trrápido", youll see thats easier. That's the way chines studenyd learn to pronounce this complicate sound. Hope you find this useful! Welcome anytime to take classes with me to practice if you want 😊