A characteristic of a great print is that your eye can explore it and not get distracted by some flaw that could have been improved with a little dodge or burn.

I stray from tradition on this... I'll consider a print good if my eye can explore it and see some flaws but not glaring distractions. If it would take much work to make only a modest improvement, I will consider accepting the print as-is.

The best manipulation is that which you can't even tell was done.