The mix is the most difficult part for me. OF course, i've only been making tracks for a little less than a year, so I am still spending a lot of time on trial and error (I find that while it helps to read about how other people do it, the sound I like is never the same as others, and I gotta fiddle through it all till it sounds good to me). For instance, just made a track I thought really got on, then near the end I thought it sounded a little thin and maybe it ought to have something else. So I slapped a little distortion on the Master Out, and all of a sudden I had a good warmth, but all the levels were jacked. frustration at its finest.

So my point is that I find that the mix is terribly difficult.
(plus, I think my headphones are dying)