I was unceremoniously dumped out of a cartage truck and left with a pile of gear on a loading dock on many occasions.
I felt it was way better than any schooling I had in media production.
Often times it hurt... sometimes it worked out gloriously.
I feel that the best thing you can do is get time in the saddle. If you can find a class situation where that is possible... do it!
If you are considering paying money to watch someone else do it... Call Danny Danzi* for an actual personal video consultation on your personal music.
Watching other people do it is great... but you need to have a full understanding of the context.
If you are dumped on loading dock and left to mix a band that knows exactly what they want... the context becomes alarmingly clear. :-)
Time in the saddle... especially with good content to work with... that's the key. Working with bad content makes it so much slower and you never know what it could have been.
Get as much mixing experience as you can the way you can make it happen for your self.
Oh and always, always, continue to advance your listening skills. At some stage in your personal journey you'll realize that your listening skills are more important than any mix recipe you will ever consider... that happens once all the tech starts to fade in to familiarity.
best regards,
mike
* that's a for real endorsement Danni... I think your hands on one on one approach is the snizzle. ;-)