I am of the opinion that you don't teach anything, it's the person that learns something.
So, I'd go for what others have already mentioned. Learn about the person, how they are, how they learn better, what are their interests.
Find something they like and enjoy, so they are motivated in learning.
Be ready and available to answer questions and adapt to their rhythm and needs.
Prepare materials and different options so they can chose their path as they go.
Facilitate them changing their mind, going back and forth, making their own mistakes.
In my case, for example, I learn by doing, and pair programing with somebody helps me a lot, but other people might prefer having a theoretical background first and will want to read a book before diving into coding.
EDIT: adding paragraphs for clarity
So, I'd go for what others have already mentioned. Learn about the person, how they are, how they learn better, what are their interests.
Find something they like and enjoy, so they are motivated in learning.
Be ready and available to answer questions and adapt to their rhythm and needs.
Prepare materials and different options so they can chose their path as they go.
Facilitate them changing their mind, going back and forth, making their own mistakes.
In my case, for example, I learn by doing, and pair programing with somebody helps me a lot, but other people might prefer having a theoretical background first and will want to read a book before diving into coding.
EDIT: adding paragraphs for clarity