The tracing on the ground and on the walls is a primordial step which must be done with a great precision in order to succeed in the implantation of the partition.
With a laser level, project on the wall the location of the upcoming partition.
Point markers in pencil.
To draw the verticals, use a chalk line drawn between two points (at the top and bottom of the partition).
Make the layout on the floor and on the ceiling, this time using a ruler placed on the right side of the laser beam.
For angles, use a Mason square to draw alignments of well perpendicular partitions.