If someone wants to learn how to speak chinese, the best way IMO is to repeat and mimic the sound of a native speaker over and over again. I used Glossika (glossika.com) 3 or 4 years ago when they were just selling a zip file of MP3s. So rather than trying to master individual tones out of context, you learn how to say words within a sentence context. And through space-based-repetition and daily practice, these sounds get more easily embedded and familiar with your tongue and your listening ear too. So rather than trying to memorize a bunch of tones, you're learning how all the sounds and words flow together, and that's how you learn to sound like a native speaker.