How to Prune western red cedar?
None required, unless grown as a hedge

western red cedar · Thuja plicata
Also known as: British Columbia cedar; Californian white cedar; giant arbor-vitae; Nootka Sound arbor-vitae; western arbor-vitae; yellow cypress
Grows best in moist but well-drained soil. Protect from drying winds especially when young. Suitable for hedging or screening
None required, unless grown as a hedge