Shaping a lemon tree is as simple as cutting the branches into your desired look. It is best to aim for a rounded, symmetrical shape to the top of the tree and always keep in mind that a good pruning process includes knowing when to stop. A good rule of thumb is never to chop off more than one-third of the tree. If you prune too much, you could put unnecessary stress on the plant. Never substitute the health of your tree for aesthetics, as you’ll be creating more work for yourself down the track.