The right tool makes a job easier, and pruning is no exception. You want to make cuts that will heal quickly, without jagged edges, and that means the tools need to be sharp and appropriate for the size of the branch. There is a wide variety available, but, for most jobs, a pair of pruning shears and a lopper with a saw for larger branches will suffice.
Hand pruners, or pruning shears, can be operated with the fingers of one hand, They're indispensable additions to a gardener's tool kit and come in a variety of styles, from narrow blades that are particularly good for cutting flowers to extra large ones for thicker branches. Hand pruners come in two styles: bypass, with blades similar to a pair of scissors; and anvil, with a sharp blade that comes down squarely on to a piece of metal, the anvil. Bypass pruners leave a cleaner cut, which is better for living wood, while anvil pruners often crush the stem. If you buy only one, make it the bypass style. If you tend to misplace tools, wrap red tape around black or gray handles to make the pruners more visible in a pile of leaves or a clump of long grass.
Loppers are like large, two-handed pruning shears and come in bypass and anvil styles. In addition, types with ratcheting mechanisms that make cutting through thick branches much easier are available To cut higher branches without a ladder, consider loppers with handles that extend, giving you a foot or more of extra reach, or the long-handled pole pruners that allow you to reach branches 5 to 6 feet above your head. In general, buy loppers that are light and easy to hold horizontally for long periods of time. Aluminum handles are fine, but wood is almost as light, just as durable and probably less expensive. Extendable handles can increase the weight, but may be worth it for their versatility.
Loppers can handle branches 1 to 1-1/2 inches in diameter, depending on the hardness of the wood. For thicker limbs saws are necessary. Small, narrow saws with a curved blade that often are sold for camping do quite well for pruning in narrow places or among a thicket of branches. Longer saws with rounded handles, called bow saws, are excellent tools for large branches and have replaceable blades.
There are a variety of electric reciprocating saws and chain saws available that may be helpful in pruning large branches. Chain saws leave a rough surface and should only be used to cut away the outer portion of a limb, leaving a stub to finish off with a finer saw. Reciprocating saws will leave a smooth surface if you use a fine-tooth blade but will be heavier than a hand saw, no small consideration when you're holding it up for five minutes or more.