I have a huge collection of JVC Earphones, most of them are JVC Marshmallow earphones in different colors
I use as many kinds of output devices as I can for my mixes now. First I do the mix on my desktop's surround system with sub-woofer, then I take my in-ear JVC earphones, check and tweak it as needed on them, then while testing on my JVC earphones, I turn down the master volume of the mix to barely audible so I can hear which instrument is louder/quieter than others so I can raise the volume without clipping it.
After that I test it on my standard quality headphones. Then I test them on my JVC studio quality headphones (Yep I'm a JVC fan when it comes to audio devices
even got my car's stereo by JVC
). Same drill as with my earphones.
The last step is testing the mix in my car if I can
I throw it on a USB drive, stick it in the JVC stereo and listen to it, write down any adjustments if needed, and that's my circle
PS: No JVC Advertisement intended
EDIT: Also, if someone is interested, JVC Marshmallow earphones are very common here but many people still prefer cheaper stuff. One pair of JVC Marshmallow costs around $20 here. They're very good quality earphones and extremely durable. I'm a heavy music listener, whenever I'm on the bus or something, I'll have my earphones on my cellphone almost the whole time
One pair of my JVC earphones is still serving me after a year of extremely rough use
tugging and pulling and twisting and whatnot.