Younger peach trees are known for being easier to prune to produce new growth, but just because you have an older peach tree doesn't mean that it won't produce any fruit. Take some time and patience to prune it, focusing on shaping it into a bowl shape with three to four branches shaping it. Prune the older peach tree in the springtime when you can see the blooms.
Prune any growth in between the 3 to 4 large branches that create the bowl shape. Also remove any dead, diseased or broken branches hanging off. If the old peach tree hasn't been shaped, use a pruning saw because the branches will be thick and strong.
Prune back any branches that are growing outwards, sticking out of the tree at odd angles. These will break under the weight of fruit. Leave 4 to 5 thick branches that grow off of each of the 3 to 4 trunks that form the bowl shape, if possible.
Prune smaller shoots of the branches once you have shaped it with the shears. Trim off any branches that grow outside the shape. This encourages fruit production and a healthy peach tree.
Repeat this pruning process early every spring.