Firstly i would recommend that you get some training that is accredited and some public liability insurance,
you are breaking the law working on the public without these things,
as for electric files they are very dangerous if you have not been taught how to use them,
your therapist showing you how is not enough unless she is a training provider and can give accredited certificates that are recognised by the guild or babtac hth
i went to your profile before replying to you and it says there that you are not a hair, skin or nail geek.
This is a professional forum that gives out advise to people that have already taken training in the area that they need help with.