Gently grasp the pears and lift and twist slightly. Pear should come off the tree easily, without tearing. Handle them carefully - although the pears seem firm, they will bruise if handled roughly.
Plums are easily harvested by shaking the tree and holding a tarp to catch the fallen fruit. This will cause the ripe fruit to fall and leave unripe plums to ripen in the tree. Watch out for falling fruit
Grapes are best harvested with a curved knife, scissors or hand pruners.