A user on the MSOfficeForums wanted to know if it was possible to add a milestone on task bar in the Gantt chart section of a Microsoft Project schedule.

My solution is to

1. Add a start custom field to the schedule and manually select the milestone date

2. Add a new bar style with a milestone shape and this new bar style should use the start custom field in field

For detailed step by step guide, watch this YouTube video.

Note that for this solution to work, the Task Mode must be set to Auto Scheduled.