The answer to 'how to maintain toilet' is to regularly clean and inspect your toilet to keep it functioning properly. This includes flushing the toilet regularly, cleaning the bowl with a toilet brush and toilet cleaner, and checking for any leaks or other issues.
It's also important to inspect the toilet tank and make sure the flapper, fill valve, and other components are in good working order. You should also check the toilet's wax seal periodically and replace it if necessary to prevent leaks. Finally, be sure to clean the outside of the toilet with a disinfectant cleaner to keep it looking and smelling fresh.