As many pears as you can handle
A bowl of water with a splash of lemon juice
As much syrup as you need
As many jars as it takes
Any flavorings you fancy to add excitement to the fruit (I went with slices of ginger and cardamom pods, but you can try vanilla beans, cinnamon sticks, thyme sprigs, etc.)
A splash of booze (optional - brandy makes for a traditional pairing)
Sterilize your jars, either in boiling water or a dishwasher. Distribute any desired spices among the jars.
Peel your pears, and cut them in half to remove the seeds (a melon baller works wonderfully, but a knife also does the job) and any remaining stem or blossom bits on the ends. Some pears also have a tough string of membrane running from the seeds to the stem -- remove this if you see it. Leave the pears as halves, or cut into quarters if you desire. Drop the segments into the lemony water to prevent discoloration.
Prepare your syrup: I favor a medium syrup, of 2 parts water to 1 part sugar. Make as much as you'll need to fill your jars. Add a splash of booze to taste, if desired. Bring to a boil.
Fish your pear segments out of the lemony water. If you have firm pears, simmer them in the syrup for five minutes. Remove the segments with a slotted spoon, and place in your jars, shaking them down a bit to fit in as many as possible. Pour syrup in the jars up to the bottom thread. Free any trapped air pockets with a sterilized spoon or knife, and add more syrup if needed. If you have softer pears, skip the simmering and add them directly to the jars. Unlike the pre-simmered pears, they will do a bit more shrinking, so pack them in tightly. Top with the boiling syrup, and remove any air pockets.
Top jars with sterilized lids, screw the rings on finger-tight, and then process in a boiling water bath (20 minutes for pints, 25 minutes for quarts). Remove and cool, then check that the lids have sealed. The syrup will infuse the pears (and vice versa) as they sit. By winter, they'll be amazing.