By the way, the answer is to leave as much as possible of the lower branches as long as the diameter is not sufficient to compete with the trunk. For live oaks, pruning the lower branches to a cone around the trunk is acceptable. The longer the branches the larger and stronger the trunk will grow. Pruning to about 20" diameter cone around the trunk would work. Then as the canopy develops and becomes about 90% of the entire tree canopy, you can prune the lower branches to the main trunk.