I bend the diptube up and away from the bottom center and that seems to work well. You can cut them too, but I have never wanted to do that, not that I see myself using them for serving in the future :-)
Sometimes you may get debris and yeast at the start but it has never really been an issue considering how well they work otherwise. I usually rack to a conditioning/bright tank before then going to a final serving keg, so the last debris settles out there anyway. If you don't plan on moving your serving vessels you don't even need to worry about the middle step as it is preference.