When I've had to do this, I only laced the right forward pointing spokes. On a stiff rim 8 or 9 spokes is fine (32h, 36h) With a very flexible rim I lace all the right spokes in the same direction to reduce the unsupported distance between the spokes. Lacing all the same way is fast and easy, you lace it as a radial so the spokes stick out a lot and it's easy to spin nipples on (all the same distance, ie. to top of head). Then the spokes will tension when the rim is turned to remove the freewheel.