After learning Mandarin in a non immersive  environment, I have been rather disappointed at my progress. Progress in my definition means being able to feel the correct spoken word. I find copying the teacher's pronunciation fairly straightforward. Yet later, after a lesson has finished, I will make exactly the same tone errors. The teaching adage of getting the student to speak more seems to make little improvement for me. I find little sense in learning streams of vocabulary if I seem to always get the basic words wrong! If the basic words are pronounced incorrectly, it's very hard for a native speaker to understand, even if one's grammar is correct. Thus, I feel very frustrated that I cannot even move off a very basic platform of proficiency despite the time I have put in. For those intermediate to advanced chinese mandarin learners, what strategies have you used to overcome this issue to be able to to internalise and reproduce the correct tone within spontaneous sentences consistently?