Monsteras usually put out roots at the leaf nodes, especially lower down on the stem. I just leave the plant how it is and cut between the rooted nodes. Left for a while, the nodes heal over and sprout shoots. Once they're established they can be moved out. There might be better methods but that one works for me.
Take a cutting with 3 to 4 nodes or leaves and be sure to get some aerial roots they will transform into feeder roots once in the ground. To large of a cutting will result in death to the top portion of the plant. I usually get cuttings with 3 to 5 leaves.