Don't try to change the pin oak's shape by pruning.
The pin oak (Quercus palustris) has a characteristic shape. It has a long central trunk. Its upper branches always lift to the sky. Its middle branches extend more or less horizontally from the trunk. Its lowest branches always droop toward the ground.
The pin oak's shape is usually described as pyramidal or sometimes as conical. The unique angles of its branching and the presence of many pins --short stubs on the trunk -- are reliable clues to its identification.
A pin oak tree will do its best to maintain the characteristic shape of its species. If its lower branches are removed, the next branches that are lowest on the trunk will gradually begin drooping toward the ground. For this reason, pin oaks are not very good for planting along narrow streets or in parking lots.
I hate to see a pin oak that's been deformed by excessive pruning in an effort to keep its lower branches from drooping into human zones. Here's an example of what I'm talking about -- a much abused pin oak that grows in a field of asphalt near the Bradford Square Mall in Hopkinsville, KY.
Why don't landscapers think about the size and shape and spread a tree will have in maturity when they plant it? Thinking ahead would be so much better than spending years fighting the natural tendencies of a tree. Just my opinion.
Photo of pin oak in winter provided by Robert Underwood.