Lots of advice here. most good
Some seem to come from google searches and youtube videos?
I have a friend who makes a living fixing rooms and helping small to big rooms sounds better. He said 80% of the time he walks into a room, tests it, and removes the corner bass traps. It's a huge internet trend to trap the corners and he said many many rooms just don't need it.
That said some treatment is good, but without the knowledge of amount and placement, your room will just sound different not better.
Getting used to the space your in is the best bet. For example, spend a month straight listening to all your favorite albums in your room on your speakers. Then spend some time listening to your music and comparing the level of bass to other instruments and to vocals. This way you will learn how your room makes other's music sound.
Another tip is to always A/B your music to other's you think sound good, when mixing. This way the relationship of tones will more correct.
Headphones are always good. I tend to listen part of the time in phones no matter where I am just as a secondary reference
The final suggestion is to get your ipod, iphone (or back in the day the CD player) ready, and take the mix to your car. Heck for some mixes and mastering I actually take the laptop to my car and mix. The reason is i spend alot of time in my car, so I understand the speakers really well.
Hope these help
p.s. there's no magic answer either. I remember hearing that Kanye West had the engineers remix a song of his over 20+ times because he would take it into a certain club or friend's studio and think it didn't sound good enough lol. Bottom line no one will ever be 100% satisfied with a mix, we just need to become ok with good enough