Most houseplants thrive in a well-draining potting mix. A good all-purpose blend is 60% potting soil, 20% perlite, and 20% orchid bark. Succulents and cacti need even more drainage — try 50% potting soil and 50% perlite or coarse sand. Aroids like monstera and philodendron love chunky mixes with bark, perlite, and charcoal.