I will propagate geraniums using vermiculite and rooting pots currently sold at Gardening Lab.
For cuttings where success or failure doesn’t matter, there are many other methods.
But if you absolutely want to save your cuttings, follow the method shown in this video!
00:00 Preparing the cuttings
04:57 Disinfection
05:38 Sealing the bottom
07:30 Rooting process
09:32 Post-care instructions