Summarize:

Optimal tree growth can be promoted by choosing 3-5 branches located 18–36 inches (46–91 cm) from the ground. These will serve as your primary fruit-producing branches.  It’s best to choose branches that are growing outwards away from the trunk, rather than straight up, as vertically-growing branches are more prone to snapping off if they produce a lot of heavy fruit. Think of a clock, and look to keep branches growing outwards at about a 2:00 or 10:00 angle.  All of the scaffold branches should be evenly spaced around the trunk of the tree so that the tree’s structure is well-balanced.  Mark these scaffold branches with a piece of brightly-colored ribbon or string, so you won’t accidentally trim them later. Keeping these intact will help prevent over-pruning and ensure your apricot tree’s overall structure is sound. Use a shears to clip thinner, new branches, or use a pruning saw to cut thicker boughs. Look for the collar at the base of the branch. This is a thicker, ridged area of bark that connects the branch to the trunk. Cut the branch just outside the collar, as this region promotes formation of new tissue and cutting it can cause damage and introduce decay. There should be plenty of space surrounding your tree’s primary branches. This helps promote adequate air circulation and lets sunlight reach all the way down through the tree to apricots on the lower branches. Thinner branches towards the top of the tree can be left a little closer together, whereas the thickest branches towards the bottom need the most space. Aim to remove about ⅓ of branches overall. Apricot trees tend to grow quickly and therefore need more pruning than some other fruit trees. You should be left with sparse but evenly-spaced branches throughout the height of your tree. Cut more branches off of young trees, and less off of older ones. During an apricot tree’s first three years, prune aggressively to aim for growth rather than fruit production.
Choose a few healthy scaffold branches that you want to keep. Cut most of the remaining branches about 0.25 inches (0.64 cm) above where they connect to the trunk. Prune branches located within 8–10 inches (20–25 cm) of your scaffold branches. Thin out the entire tree by removing extra branches.