For the better part of a decade I cared for Brooklyn Botanic Garden's tree collection. In that time I came to respect plants' limits and learn how to help them manifest their essential character.
HOW I SEE TREES
You should know that I really love trees. I love that every specimen is very much itself - that two trees aren't the same simply because they're the same species or cultivar. A tree isn't necessarily "young" because it was planted just a few years ago. (It may exhibit traits of old age as a result of stress), nor is it necessarily dangerous because it's large, nor unworkable because the canopy is dense. Each specimen is unique, warranting sincere consideration before trying to align its constraints with our desires.
HOW TO GET THE MOST OUT OF TREE CARE
Start with feelings or objectives rather than prescriptions. Sentiments like "I'd like more light" or "it's feeling chaotic" allow room for skillful, tree-centered consideration. Prescriptions like "I'd like that branch removed" may result in damage where other methods could have achieved the same ends with less damage.
YOU SHOULD KNOW
Pruning is wounding - categorically. Big cuts are big wounds and small cuts are small wounds. Trees tend to respond more effectively to small wounds, while big wounds can lead to disease, decay and increased risk. Skillful pruning often involves making a large number of small cuts rather than a smaller number of large cuts. This can be labor intensive by comparison, but is much more refined aesthetically and can prevent serious damage that costs more to manage over time or even necessitates removal.