Firstly, it is important to highlight that different areas of Spain and the Spanish-speaking world have different ways of pronouncing the same word and there are varied accents so there isn't necessarily a one size fits all. I would ask the student what area of the Spanish-speaking world they're interested in and explain my accent and how I have developed that. Secondly, fluency and 'natural' pronunciation comes with practice and with confidence therefore I would suggest speaking as much as possible by yourself and in a group. There are excellent language cafés for example outside of lessons. But importantly, in the lesson I would concentrate on inter-personal, oral skills. I would challenge the student with 'difficult' words and tongue twisters. However, I do think that getting a general flowing conversation is great for confidence and offers a natural opportunity for me to analyse and correct their pronunciation mistakes. I would also suggest implementing Spanish Netflix into our lessons. So for example, the student could watch one or two episodes of 'Chicas del Cable' (or any other series they prefer) during the week as being exposed to native Spanish is so useful. And then we could have a conversation discussing the topic during our next lesson so that the student benefits from hearing native Spanish and then gets to practice it through a fun topic.