Teaching Thinking Patterns

How do you teach a thinking pattern? In my previous job I worked with a data analyst, who was really good at thinking about how our data correlates among itself. He was good at the data analysis, good at thinking up relationships, and good at coming up with complex comparisons.
However, he wrote some pretty funky SQL. We had him take a course in basics of MySQL, and from time to time I’d take a gander in the slow query logs and pick a few queries and point out the good and bad things. Most of these are optimization tips, such as “Indexes don’t apply to columns when you’re applying a function to that column”.
But it’s hard to try to think outside of your own box, and even running EXPLAIN on every query won’t necessarily tell you how you can fix a query. The problem is that there’s no way to know if you have optimized the query as much as possible. Even experienced DBAs
I was often frustrated when repeating concepts — though I always took a different approach, since I find that if I have to repeat myself it means that it didn’t sink in with the way I said it before. But I know many people, myself included, have managed to learn how to think differently.
The question, I guess, is how do you help someone else think differently?