Try learning the names of your more important trees and be able to recognize them in “the wild”. Notice any differences such as leaf size or color. Differences could be evidence of health concerns.
Arrange for annual inspections to help spot problems before they become an issue.
Many insect problems are brought on by a tree’s poor health. Unhealthy trees emit odors that attract borers and bark beetles that can cause irreparable damage.
Look for deep “V” shaped crotches in trees. These are potentially dangerous, allowing the tree to split apart in heavy winds. Very often, this can be addressed with installation of support cables.