The most important element in the deterioration of soldering iron bits is long idle times. This is where you leave the iron on, and not in use, for a long time.
Have everything ready when you start soldering, so the iron will be used continuously, and will not sit there building up heat, while you get ready to use it again. An idle iron will keep heating to its maximum capacity, and without anything to transfer the heat to, it will start burning off the tinning, after a short while. So if you will not be using the iron for a while turn it off until you are ready again.