This is a schedule we have used for a long time when our son went to bed. Whenever he was distracted we only needed to ask what was done already and he went on with the next step.
After a while this schedule became his normal bed ritual and it was no longer needed.
This schedule as a PDF: Going to sleep
And a Picto Selector Export file: Going to bed.pszip (Use this file to edit this schedules to your own needs)