If you've kept a front-loader working for 13 years, you are doing all the right things. But, since you ask:
1) Keep your door open between loads.
2) Be paranoid about your pockets. I get a lot of problems in front loaders from pebbles, pennies, dimes, guitar picks, etc., etc.
3) Don't slam the door.
4) Check your standpipe, make sure it's draining the water well. If water starts to back up the standpipe it can back into the machine and cause awful smells.
5) What applianceman said above about soap: rust and mold are usually due to oversudsing. Most people are using too much detergent.
6) Be paranoid about your pockets. Yes, I said that twice.