Mark where the vertical studs will go on the top and bottom plates by tracing around an offcut of framing timber with a pencil. Put a stud at each end and space the others evenly along the frame every 600mm. Spacing them like this will make it easier later when you want to cover the frame.
Measure and cut eight vertical studs, all 95mm less than the height you want for your frame. The studs are 95mm shorter than the height of the frame to allow for the thickness of the top and bottom plates. We add 5mm to allow for any variations in the height of the floor. Nail the studs into place between your top and bottom plates to create the two sides of your frame.
Straighten the outside edge of the frame with a spirit level and measure the distance between the two sides. This gives you the width of your end pieces for the frame. Use this measurement to cut top and bottom plates for both ends. Then cut three vertical studs for each end, using the same length you used for the previous studs. To assemble each end, nail three studs between a top and bottom plate.