Word. I agree with the aforementioned make a cd.
Any recording i have done or mixed i always listen to it on anything that will play and make little jot notes about what sound good or bad on what device.
This is just my opinion but there are so many consumer based outputs geared more towards low end boosts like bass boost and shit built right in, its hard to get a good grasp on what it sounds like, you know?
So try it on lots of stuff, your car, your dads car, your aunts Walmart clock radio, cheap headphones, top of the line headphones.
Also another tip that works for me for mixing final levels and tones, and again this is only me, i do it at different volumes. Kinda helps me out. Distorted guitars i find may sound nice at a comfortble level but ill get them in my car and crank it and the mids are 9 times in 10 way to high and deadly.
Thats my adivce for whats it worth.