I have created a course specially to teach such a methodology of Rashi's approach to Tenach. It has been successfully taught to adults, children, teachers and parents.
It is very simple and works on just 10 categories such as
1. Unusual Word,
2. Grammar,
3. Excess Detail
4. Something Missing
5. Repetition
6. Repetition with a Difference
7. Ambiguity
8. Unusual Object
9. Names, Places, Dates, Numbers
10. Logic
Rashi typically asks an (unarticulated) question from one of these 10 categories and proceeds to answer it within his commentary. Once you can identify these categories, you have a framework for understanding Rashi.
Within each category there is some specialised expressions which leads on to a Rashi "dictionary" of key terms that I have created and which reference Rashi's commentary by pasuk.
It works well and gives students of every age group and even with a very limited ability the confidence to learn Rashi.
Michelle Sint