There will be plenty of opportunities to correct anything that might be going wrong, without trying to do everything at once.
For example, if a student is having difficulties keeping both hands on their respective sides of the keyboard, you will have limited success also trying to focus on the fine motor skill of the home key placement.
In other words, any problems with technique need to be tackled individually, and in a sensible and logical order.
Observation before action
This is where our earlier advice about observing typing technique, really comes into play.
Try and judge what you are seeing objectively.
Endeavour to determine the cause of any difficulties, not the effect.
For example, a student may consistently be hitting the T key when they mean to press the R key.
However, you have observed that they hold their elbows wide, making their hands point inwards. So, when they move their left index finger straight upwards - the movement normally required to press R - they are actually moving diagonally towards T.
Therefore, to correct the problem in technique, it is the elbows that need your focus, not the fingers.
With careful observation and appropriate intervention where needed, your students can achieve success!