To prune well it is important that you use the right tools they should be sharp and not rusty. As plant sap is corrosive it is important that after use the blades are wiped over with an oily cloth.
Secateurs are perfect for small branches. This tool allows you to obtain a very clean cut if it is kept in good condition. There are two types of secateurs, the traditional one has a curved blade that cuts against a fixed blade: a recent innovation is the anvil secateur which has a D shaped blade that cuts against an anvil. To achieve a good cut with either model the branch must be positioned as far between the blades as possible and not at the tip. Battery operated secateurs allow branches to be cut with ease even if quite thick.
The pruning hook is ideal for reshaping a tree where the branches to be cut are high up and you don't want to use a ladder. It is simply a secateur with a long handle of between 2 and 8m.
The branch cutter or lopper is a pair of giant secateurs with handles between 20 and 40cm long which allows you to exert a fair degree of force, more useful when larger branches need to be cut.
A saw or even a chainsaw will be necessary for big branches and will prove useful for felling trees. There are several models of saw, even folding saws that are easier to carry safely. There even exists small battery powered chainsaws, the gardener's dream!
Hedge cutters are an indispensable tool for cutting hedges. The handles are set back so minimizing the risk of injury when in use. Whether they are hand operated, electric, petrol or cordless, they still require a certain degree of know how. Work using small cuts only opening the blades as much as necessary and using the tip of the tool to trim the plant. This helps you control the tool and will make it less likely that you end up with holes in the hedge or badly pruned branches.