Prune your cypress in the spring once the danger of frost has passed. Pruning encourages new growth, and new growth needs time to harden off before winter.
Cut all dead and diseased wood first. Trim all dead wood and diseased wood back to healthy, green wood.
Remove brown branches that are growing only on the inside of the tree canopy in order to open the inside up to more air and sun. Cut these brown branches back to the trunk. Do not cut branches back to the trunk if they have green growth on their tips.
Cut the tips of branches in order to create a uniform and straight edge to your tree, sloping gently upward. However, never under any circumstances cut all the way back to brown leaves or branches. Your cypress will not fill in the brown patches--these will remain "holes" in your cypress for many, many years. Cut back only to green leaves and green branches.
Cut straight across the top of your cypress when the tree has reached the height you want. Each year trim the tips of branches that grow taller than the height you have selected.