Soak & dry checker.
Succulents and cacti store their own water, so they want the opposite of most houseplants: a thorough soak, then a long dry spell before the next drink. Tell us the plant, the season and the setup for a starting rhythm - but the real rule is simple: only water when the soil is bone dry.
How to check it's dry: push a wooden skewer or your finger right to the bottom of the pot. Comes out clean and dry? Soak it. Any damp soil clinging on, or the pot still feels heavy? Wait and check again in a few days.
Leaves turn soft, mushy, translucent or yellow and drop at a touch; the stem base blackens. Stop watering, let it dry hard, and behead-and-reroot the healthy top if the base has rotted.
Leaves wrinkle, pucker, go thin, soft and floppy from the bottom up. This one is easy - give it a good soak and it plumps back up within a day or two. Far safer than overwatering.
⚠️ When the soil check and this estimate disagree, trust the soil - always. More succulents die from staying wet than from thirst, so when in doubt, wait. Pots without a drainage hole, cool rooms and dense soil all hold water far longer: lean drier still.