Identify a cactus before setting up its care. A sunny desert species and a forest cactus can need different conditions, even when sold on the same shelf.
A cactus name matters more than a universal schedule
Desert cacti, epiphytic forest cacti and grafted specimens have different growing requirements. Keep the species or nursery label and note the condition of any rootstock. A round shape alone does not establish the routine.
Choose a manageable container
Use drainage and a growing mix suited to the plant. Match pot size to the root system rather than giving a small cactus a large reservoir of wet compost. Stabilize it without burying the stem base unnecessarily.
Water for growth and drying
When watering is needed, reach the roots and let surplus leave. A few surface drops each day do not supply the whole root ball reliably. Cooler, slower growth can extend the interval considerably.
Repot safely and for a reason
Use appropriate tools and protection to avoid damaging spines, skin or plant tissue. Inspect roots and allow suitable aftercare after disturbance. Lack of flowers is not proof of poor care or a reason to apply stronger feed; age, species and conditions all affect the result.
Related reading
Cactus Care Mistakes: Roots, Repotting and Growing Conditions