My grandpa used to pick sturdy branches on his peartree and wait until blossoms had formed tiny pears. Then he’d pluck all but the best one off and tie a bottle over it.
He’d take the bottles down when the pears inside were still green but full siized and let them ripen in the bottle, off the tree. Then he would pour some cheap awful white rum in the bottle, cork it and leave it sitting in the dark for a few months. Absolutely delicious.
I have done the same just using canning jars and with different varieties of fruit. You can add sugar if you want a sweet liqueur. Grapes and cherries and apples are nice, everything with a tight skin works. The pears are best though.