Teach English and Spanishto students who have a solid foundation but need to progress on their ability to speak and write english

I am an Erasmus student from Spain I study Business Administration in both Spanish and English, I have lived 2 years in the US, have studied other 2 years under an international curriculum and have an official C1 in English and native level of Spanish. Not only am I used to using both languages both for school,and informal settings but I also count with a solid foundation of teaching since I have volunteered in several organizations to teach both languages to international students and groups at risk of social exclusion. I have worked with students from the age of 5 up to the age of 60 which is why I often personalize lessons and try to focus on individual progress instead of using standarized methods that may not take into account the particular challenges of each student. More or less I have been teaching English and Spanish for around three years with different purposes such as to use at work, pass a test, improve grammar or speaking, etc.