Links and LJ-cuts: Generally, I click them if they look to be something I want to read, and if they won't occupy too much of my time. If I'm rushed, or if I miss checking LJ for a few days, I'll tend to skip them more. Also, when I'm reading the LJ of a prolific poster, I'm more likely to skip.

Also, I'm more likely to read an LJ-cut than a link. I think this is because I already expect to like the writing of the LJ writer I know, and the link is an unknown quantity. ('ts'why I tend to reread books and rewatch movies, too.)