The markers are set up by clicking within the preview area in the 'Mix window' (in New Marker mode).
In this area, the mouse cursor changes its shape into a little cross. To make it easier one may turn the 'Zoom' window from the 'Window' menu. Markers can be exported and imported into another project.

It is possible to move marker or group of markers by directly clicking on it and drag to a new position. To select more than one marker you should to hold Ctrl key during dragging. You can also select multiple markers in the Project window. Right Mouse Button Click on the marker shows context menu with 'Set Marker Properties' function.

You can also toggle grid view. Grid is proportional to the preview and resizes with it.