What's your method for dealing with underfull/overfull \hboxes and unacceptable badness in general?
LaTeX has the \sloppy command which IIRC sets \tolerance to 9999, and \emergencystretch to a large value. But the default \tolerance is 200 (I think), which is a big difference. It's very "either/or" when maybe there's a more optimal way.
For my native language (swedish) I've found that many issues arise because TeX doesn't find all the possible hyphenation points, so I usually spend time adding words to the hyphenation list.
But still, in any longer text there's usually a couple of paragraphs that just won't set right, I'm curious about your tricks or methods for dealing with them.