Here's how I take care of my ears:
-NEVER, EVER listen music longer than 1 hour a day. Every Thursday and 24th of a month, it's a no headphone day for me. Unless I am a visiting headphone shops but usually, the day after it, I will stop myself from listening music through headphones.
-Volume limit, not more than 10% of the maximum volume in my MP3 Player for my IEM. Anything more than that, I will give up listening specially while on the plane, I never listen.
-Washing my eartips every week to my ears away from bacterias. Also, cleaning my ears. Sometimes, I skip listening music at this day.
-I never lent anyone of my IEM with my own eartips size on.
-Never listen music while walking on the street. Don't even think about wearing it around your neck as this will trap dust. Listening music on the street can cause accident it happens everytimes on the news!
-Don't touch my earphones with dirty hands! I don't want to wear bacterias or/and germs!
-Using a clean dry cleaning cloth to clean my earphone housing. Keep it in the case provided whenever I am not using. Even at home so that it won't get exposed to dust.
-Never leave it in a car under the sunlight because I don't wanted my silicone eartips to burn and "chemical reaction" and stuff like that.
-After le me lent anyone eartips, I don't wear it unless I clean it.
-Never bring it for a jog. I did rather jog without music than taking the risk. I don't want my sweat to drop into the earphones driver and cause electric shock. <-possible? lol
Soo....errr, that's how I kind of protect my hearing safety. Might be too strict for a high school teenager, but HEY! I haven't get to try the Sennheiser HE90 xD