Regarding headphones choice I would pick up phones with a response curve near Harman curve.
That does not work for me, because it is skewed for bass head consumers who like artificial bass tones. The bass no longer sounds punchy, tonal and natural - just thick and rumbling. No Harman Curve here.
ATH-M50x are very good phones for tracking and could be used for mixing as well,
I sold my ATH-MX50 headphones with no regrets. To my ears, they are heavy handed high and low, bass heavy and lacking sufficient sizzle in the high frequencies. I enjoy jazz recordings where the snare and cymbals are crisp and just sizzle. I also sold all of my so called "audiophile" headphones, such as the ATH-AD900x because they lack sufficient bass and are sibilant to a fault with far too much sizzle; to the point where it was uncomfortable. Something in the middle that sounds natural as if I am on stage with the musicians, and not in the audience listening through a PA, works for me. I recently acquired a pair of Austrian Audio headphones, but the jury is still out deliberating. Time will tell.
I was in a couple of really lousy bands in a former life. The take away is, I sort of know what the instruments really sound like in on stage, in person, up close and personal. I cannot abide fake, heavy bass or artificially excessive treble, and (while I am on a roll) typically dislike heavy compression and other effects. I want to hear the instruments in the raw, as they sound onstage like during a live concert. Imagine listening to a small classical ensemble at a reasonable distance in a proportionally appropriate room. I want the recording to be as real as possible, matching the sound, including the ambience of the venue, and trick me into thinking I was there at the time. I want my speakers and headphones to match the recording. (Impossible, for sure, but I will accept the closest approximation I can get.)
Just MY take ... James - K8JHR