Place your propagating case or pot in a bright place but not in the full sun.
After about a month or so the leaf should have rooted, and after a second month a tuft of leaves will appear at the base of the cutting. Gradually increase the ventilation in the propagator (or slit the polythene bag a little at a time over several days until it is finally removed), so that the young plant becomes used to the room temperature.
As the pot becomes full of roots, repot into a larger pot. 10cm (3½ in.), filled with potting compost (John Innes no. 2 or a soiless equivalent.)
after a few more weeks. Your new plant should start flowering after
another three months or so.