I think for me, the most important are not falling in love with the safety zone and not being patient.
I always feel like if I'm comfortable, I'm not progressing. If I don't feel like I'm progressing, it's easy for me to get complacent. However, as a side effect of this, I end up being rather impatient and expect to reach milestones much sooner than is actually possible. I find it hard to watch things play out when I'm itching to move and progress on to the next thing.