There are three different types of learners, visual, auditory and kinesthetic. As the teacher it's your responsibility to learn which one your student is and adapt your teaching style to meet their needs.
Maybe they do well sitting down and playing with the equipment over and over again to learn it. Maybe you need to set them up with the manual and that's the best way for them to learn to use it. Maybe you showing them and explaining it is what works best for them.
As far as assessment and people skills I haven't found a good way to teach that and I don't know if there is. I know some people make their quiet, reserved interns or new hires do things like always order everyone's food or coffee to force through interact with people. Not sure that's the best way to teach, by making someone uncomfortable...
Try to find what works for them.
as stated prior not everyone is cut to make it in this field. I had a girl who was book smart, not street smart and quite shy. She learned fast I was not gonna hold her hand after the first 2 days I would walk in evaluate the situation and say Your patient GO.
It was brutal tactic and I'm not a fan of it. But it worked.