If you’d like to fill your home with beautiful plants, you can buy them, like a sucker. Or you can remove a leaf or two from a plant you come across somewhere—one that won’t be missed—and coax it to grow into a full plant of your own.
I’m not saying you should pull leaves off of plants in stores, but I’m just letting you know that if you did, it would probably work. You can also ask for cuttings from your friends’ houseplants, or snip something from a neighbour’s garden or a public park. The moral and ethical implications are left as an exercise for the reader.
Succulents grow well from cuttings; here is a guide to encouraging them to take root. Herbs like mint, basil, sage, and thyme will grow roots if you just put sprigs of them into water; here’s a guide to that as well. In general, if there’s a plant you covet, google its name along with “propagage from cuttings” and you’ll find a wealth of information. Some plants don’t grow well this way, but many do. Sometimes you will need to encourage the pilfered stem to take root by dipping it in powdered rooting hormone, a thing you can buy at any garden store.
Should you get hooked on propagating plants from stolen cuttings, I should warn you that this can lead to grave robbing. Authors Tom Christopher and Marty Asher write in The 20-Minute Gardener that the best rose bushes grow in cemeteries. There was once a tradition to plant a rosebush on your mother’s grave, so all you have to do is look for a rose you like near a headstone that is very old and doesn’t look well maintained. That way you’ll know that the rosebush is a variety that grows well even if neglected, and you’ll reduce the chances of being caught in the act by a visiting loved one.