Basta follow a regular change schedule. eto lang magagawa mo from your end to maintain your AT.
Usually, good ATF smells sweet. Pag amoy sunog na, then its too late..... kelangan palitan agad.
Im not sure lang about the maintenance sched, pero the more you change it, the better. Why? kasi tuwing atf change, around 20-30% of the old atf still remains in the tranny.