When faced with a new project, the first step is not to plan your approach, but to plan your distractions. Identify all the things that will derail you from your goal and schedule them into your day.
Create a to-do list, but only of tasks that have nothing to do with the project.
Or, if you're feeling particularly ambitious, create a real to-do list.
Set a deadline that's just out of reach, but still achievable enough to give you false hope. This will motivate you to work on the project, but only just enough to get started.
Recruit a friend or family member to work on the project with you, but only if they're willing to do all the work while you provide the "direction" and "oversight".
Work in focused 25-minute increments, followed by a 5-minute break. This will allow you to make progress without getting too comfortable or burnt out.
Set small, achievable rewards for yourself after each focused work session. This will train your brain to associate hard work with immediate gratification.