Look at the CRA progression for the outcome.
Choose which strategies to explicitly teach.
Choose questions that have been given within the progression to do with students.
Develop ~3 lessons for each outcome one for each, Concrete, Representational, Abstract.
Choose Low Floor High Ceiling questions for each lesson.
Find an opener or warm up for the lesson – Number talks, fluency practice, or review question from previous lesson work well.
Choose a closing/final question that could be formatively assessed.
Add more lessons as may be needed around the CRA lesson – after formative assessment you should be able to determine if students need more of any of the CRA progression lessons, or if they need more time to practice a skill after the CRA progression has been taught.
A sample intervention learning plan can be found here.