Potting your cacti and succulent container garden largely depends on your personal taste and preference. A Cactus Potting Mix is the best soil choice. Another option is just to let them be. Let the water reach the roots and give the plant a drink. You don't have to worry about losing your Tillandsia collection because healthy air plants can make multiple offsets at the same time. Once you have taken your cuttings, leave them outside for a few more days before planting. My Aeonium arboreum Zwartkop is happy to be outside during the wetter seasons.