I've been using worked examples and self explanation prompts in teaching Mathematics for a full year now.
Much to my amazement I have managed to keep on top of my planning to allow me to have pre-written self explanation prompts available for the majority of topics I have taught this year.
My classes have risen to the challenge offered by these questions to improve their mathematical explanation.
Two ways I have found worked examples particularly useful are for comparing methods and talking about calculator usage.
Dividing Fractions - Year 7
Non calculator Standard Form - Year 10
Area of Circles - Year 8
Trigonometry - Year 9