Of course, one obvious way of maintaining the health of your tapes is to maintain the health of your tape heads and other mechanicals. Most enthusiasts recommend using a clean cotton swab dipped in anhydrous isopropyl alcohol to clean the heads on your tape decks. They then recommend that you use the dry end of the swab to dry the head. If one gets visibly dirty, they recommend replacing it with another clean swab.Most recommend that you do this for roughly every 30-40 hours of use.
A clean cotton swab with alcohol can also be used to clean the spin capstan (metal spindle to the right of the tape heads that works with the pinch roller to guide the tape), any stationary metal or plastic guideposts and under the reel hubs. A dry swab can be used on any other area inside the tape well.
If you have rubber cleaner, you can use it on the rubber pinch roller.
You can use a commercial tape deck demagnetizer...usually you do not touch the tape head with these and you must be careful because the magnetic field will pull it towards the head. Simply slowly move the demagnetizer back and forth across the area directly in front of the tape head without touching it.