The answer to 'DIY tree trimming' is that it can be done safely with the right equipment and precautions, but for larger or more complex tree work, it's best to hire a professional arborist. Proper tree trimming helps maintain the health and appearance of your trees, but improper or excessive cutting can damage them.
For small trees and branches under 4 inches in diameter, you can typically trim them yourself using hand pruners, loppers, or a small pruning saw. Make sure to wear protective gear like gloves, eye protection, and a hard hat. Avoid cutting more than 25% of the tree's foliage at one time, and make clean cuts just outside the branch collar. Dispose of the trimmings properly. For larger trees or complex pruning, it's best to hire a certified arborist who has the right equipment and expertise to do the job safely and effectively.