What is the best way to care for a betta fish?

To care for a betta fish, provide a tank with at least 2.5 gallons of water, a heater to maintain a temperature between 75-80F, and a filter to keep the water clean. Feed them high-quality betta pellets or flakes once or twice a day, and occasionally offer live or frozen foods. Change 25-50 of the water weekly and monitor water parameters regularly. Avoid overfeeding and keep the tank decorations simple to prevent injury.