Proper pruning is essential in developing a tree with a strong stucture and desirably form. Trees that receive the appropriate pruning measures while they are young will require little corrective pruning when they mature.

Keep these few simple principles in mind before pruning a tree:
-Each cute has the potential to change the growth of the tree. Always have a purpose in mind before making a cut.
-Proper technique is essential. Poor purning can cause damage that lasts for the life of the tree. Learn where and how to make the cuts before picking up the pruning shears.
-Trees do not heal the way people do. When a tree is wounded, it must grow over and compartmentalize the wound. As a result, the wound is contained within the tree forever.
-Small cuts do less damage to the tree than large cuts. For that reason, proper pruning (training) of young trees is critical. Waiting to prun a tree until it is mature can create the need for large cuts that the tree cannot easily close.

Taken form ISA Trees are Good

Thinning is the selctive removal of small live branches to reduce crown density. Because the majority of small branches are at the outside edge of the crown, thinning is focused in that area. Proper thinning retains crown shape and size and should provide an even distribution of foliage throughout the crown.
Thinning increases sunlight penetration and air movement through the crown. Increased ligh and air stimulate and maintain interior foliage, which can encourage taper on scaffold branches. Thinning a limb should be considered if cabling will be performed. Thinning also can remove suckers from the base of the treeand some watersprouts on the interior. Excessive removal of watersprouts often produces more watersprouts, so it is not recommended. Vigorous production of watersprouts on interior limbs often is a sign of overthinning, topping, or lion tailing.
Excessive branch removal on the lower two-thirds of a branch or stem (lion tailing) can have adverse effects on the tree and therefore is not an aceeptable pruning practice. Lion tailing conentrates foliage at the ends of the branches, reduced branch taper, increased load on branch unions, and weakened branch structure. Lion tailing also changes the dynamics of the limb and often results in excessive branch breakage.
If the entire crown will not be thinned, the areas to be thinned must be specified. The size range and percentage of foliage to be removed also must be specified- usually in the 10 to 15 percent range- but should not exceed 25 percent of the foliage, especially in mature trees. Most thinning removes branches 1/2 inch to 2.5 inches in diameter. If larger branches are removed, large gaps may be created in the crown, or watersprouts can result.

Taken from ISA Best Management Practices

"Cleaning is the selective removal of dead, diseased, detached, cracked, and broken branches. This type of pruning is done to reduce the risk of branches falling from the tree and to reduce the movement of decay, insects, and diseases from dead or dying branches into the rest of the tree. It can be performed on trees of any age but is most common on medium-aged and mature trees. Cleaning is the preferred pruning type for mature trees because it does not remove live branches unnecessarily.

The location of branches to be removed should be specified if the entire crown is not going to be cleaned. The diameter of branches to be removed also should be specified. This usually is done by specifying the smallest branch to remove."

Taken from ISA Best Management Practices

Topping is the indiscriminate cutting of tree branches to stubs or lateral branches that are not large enough to assume the terminal role. Other names for topping include "heading", "tipping', "hat-racking", and "rounding over." The most common reason given for topping is to reduce the size of a tree. Home owners often feel that their trees have become too large for their property. People fear that tall trees may pose a hazard. Topping, however, is not a viable method of height reduction and certainly does not reduce the hazard. In fact, topping will make a tree more hazardous in the long term.

This is one of the main phrases clients use on there Google search engine. The problem is that many companies will appear before you. How do you tell them all apart? Here are a few simple questions.
1) Are they certified arborists?
2) Is their staff trained?
3) Can they provide for not only my removal needs but fine prunning also?
4) Do they follow safety standards?
5) Do they have insurance?
6) Will the staff minimize wear on my property while working?
7) Will they treat me, my property and trees with respect?

We always answer yes to all those questions! If they can not answer yes to all of those questions then you should pick another tree company.