Most plants are easy to clone from a cutting. Anything woody, shrubby, branched, or a vine will work.
Some plants, like Angel’s Trumpet, will only grow from hard branches, others only from the soft new green ones. Most plants will grow from both.
The new roots will grow from leaf nodes that are in water or soil. Remove at least 3 leaves, and put 3 nodes below the water or soil level. If you plant in soil be sure to keep the bottom stem at least a half inch off the bottom of the pot or it will rot. I find sphagnum is the best medium for getting cuttings started.
I like to use clear plastic cups, that way I can see when the roots appear and if they are getting enough, too much or too little water.
Some plants need a bit of rooting hormone to get started, almost all won’t need it. I find the powered rooting hormone easiest to use. Wet the stem and roll it in some of the powder before planting.
Remove most all of the remaining leaves. The plant has no roots so it can’t get water to the leaves. The less it starts with the better your chances. How many depends on the size of the leaves. I try to leave about 1-2 square inches of leaf surface. If need be cut a leaf in half.
Because there is not water going up to the plant you’ll need to keep the humidity very high. Use a terrarium, plastic cup, or a clear plastic bag to keep the moisture in.
When new leaves appear, slowly let the plant adjust to life outside the humidity closure. Once it’s been adapted ( 2-6 weeks ) Replant it in soil, outside if it’s to be an outdoor plant, in a pot if it’ll be indoors.