This is a general question, I'll try to contribute my two cents.
To keep a transmission in good shape, you should avoid "heavy" driving. The rapid switch between gears can eventually cause wear and tear that requires you to replace or rebuild the transmission.
By going easy, you can extend the life of your car in all aspects. This doesn't mean you have to drive like you're an 90 year old woman, but you should accelerate smooth, and not go from 0 to 50, brake, 30 to 70, brake, etc.
Also check the transmission fluid at least bi-monthly.
You can check specific service schedules out on sites like driverside.com, or your owners manual if you still have it.