If you'd like to reuse settings across projects, use the Library to save and import settings. Learn more about the Library here.
If you'd like to reuse settings across simulations within a project, you can reuse settings from older simulations:
Click on the Results tab at the top of the page and find the desired simulation from the list. Alternatively, you can use the simulation tabs at the top of the page.
Open the simulation.
At the top of the control panel, click on Post-processing.
Select Setup Details.
Click the Copy to Setup icon (overlapping squares) at the top-right of the control panel.
Note: Clicking Copy to Setup will set the Initialization method for your physics to Existing Solution, with the simulation that you copied the settings from selected. If you do not wish to initialize from that simulation, you can change this setting, as well as modifying the other settings.