Within Teamwork Projects, once you have created a task list you can add a milestone to this to give yourself a overarching goal to work towards.
To add a milestone, choose the Tasks area of your project. On the task list you wish to add a milestone to, hover over the name of the task list and choose the Edit option.
Once this has been selected a pop up modal will appear where you can then select the 'milestone' tab. You can then choose an existing milestone from the dropdown menu or create a new one.
You can then choose the save option and the milestone will appear to the top of the task list.
For more information, see: Adding a milestone