I'm kind of paranoid about practicing at home. You know how there's that quote "Practice does not make perfect. Only perfect practice makes perfect." I always think I'm going to practice bad habits and get them ingrained into my body.
So my solution is to only practice things that literally could not be any worse. Things that I know are bad, so my mind won't start to think otherwise. Things that are so bad they aren't even at a level that corrections in class are helpful. Things like petit allegro jumps (why won't my legs assemble in assemblé???) and pirouettes.
I usually do these things when I'm already warm (after Other Movement, yoga, or ballet class), but sometimes do some basic tendus, pliés and relevés because I can't get into too much trouble with these. I'm thinking about adding a more comprehensive but still basic barre. Kathryn Morgan's "Easy Ballet Barre" on YouTube seems like it would be appropriate. I have a lovely ballet space at home (with a wall mounted barre), and it would be a shame not to use it more.
I also do flexibility and conditioning at home obviously, but I don't count that as ballet practice.
I don't practice more complex things at home that we do a lot in class, because I'd rather just work on them properly in class. I definitely don't practice anything fancy at home off of YouTube that I haven't learned in class. One of my ballet teachers yelled at a student for this, saying he could tell that he had been teaching himself off of YouTube because the move looks a certain way on video but it actually isn't that way.
This is how I approach practicing at home, not throwing shade at anyone who does it differently! Do you practice at home? What and how do you practice?