To start planning, define your goal and objectives. Then, design a series of tasks to achieve both. Knowing how to overcome those frustrations and still successfully start a task aligns closely with other executive functioning skills, such as problem solving, flexibility, and emotional control. Task analysis methods are widely accepted as evidence-based practices (PBE) and are used among special education professionals, behavior analysts, and other therapy professionals.
Behavior is a complex topic and you can't talk about behavioral objectives without also talking about FBA, discipline, demonstration audiences, etc. Focus on developing your task analysis around instructions that cause you and the student the most stress and challenges.