I'm teaching a pronunciation class this semester. I wrote my own material. It includes some minimal pair practice, some pairwork, some "tongue twisters," some jazz chants, and some work with liaisons, reductions, etc.
I tell my students that it is my opinion that my class will help their listening, but as for pronunciation, it will depend on how hard they are interested in working on it. I can be the in-class guide. They can come to me after class with questions or to see if they are pronouncing something correctly. (My class is running over 40 every day, so individual work in class is limited.)
I tell them that the most important thing is whether people understand them or not. If people understand even though they have an "accent," that is the main thing. If they want to work on becoming closer to native speaker English, I'm happy to help them, but they will have to do all the work. I tell them they can practice in the bathroom with the door shut and looking in the mirror. Sometimes you can make a perfect sound, but when you see how your face looks, you might decide that's not the best way! For example, in making the /th/ sounds, it isn't necessary to stick out your tongue too far.
I also tell them that the teacher can't follow them around, so they will have to learn how to self-monitor whatever pronunciation problem they want to work on. In addition, I tell them they should try to "correct" only one thing at a time. If they try to do too much, they will be afraid to open their mouths. The students seem to like the class. I try to make it a little funny. (All the jazz chants have a punchline.

) I think if you can laugh and learn, it will stick better.
In reality, if 10% of the class improves pronunciation, I will consider it a big success. If the rest improve their listening skills, I will be happy too.