The most important way is with maintenance. The philosophy of it can wait does not work in the "tree" world. If your tree has declining limbs or decling sections it is always best to address them sooner rather than later. A dead limb(s) allows not only a hazardous situation to exist in you yard but atrracts pathogens and diseases to enter your trees easier causing further decline. If sections of the tree or your entire tree is dying or dead immediatly removing it is safer and more cost effective. If a tree has been dead for quite some time the tree becomes more and more dangerous and brittle with each passing day. This only adds to the amount of time and equiptment necessary to bring the tree safely down. The more time, tools, work personnel will increase the cost of the job!If you ever have a question with the health of your trees call a certified arborist for a consultation. Maintenance is the key to saving money!!