In my projects I have different milestones, like end of phases, documents or reports to deliver. I insert them as such in  the project and I use the Milestones Report to know the upcoming ones and review the achived ones. For this Microsoft Project provides me  with a Milestones Report and you can learn how to use it in this video.

To understand what are the milestones ahead of you or passed ones, Microsoft Project proposes a report that shows the achieved milestones and the forthcoming ones. You can learn it from this video.