Pro tip: blue painter's tape on the mud pan lip stopped my corner bead from sliding
I kept having corner bead slide down the wall while I was pressing it in, especially on ceilings where I'm working one handed. Ran a strip of blue tape along the pan lip to hold the bead at the height I want, then mudded right over it and peeled the tape once it set up. Takes maybe 10 extra seconds per corner, anybody else got a trick for keeping bead from creeping?
That "peel the tape once it set up" part is the move people miss. Most guys pull it while everything's still wet, then wonder why the bead creeps out of place. Waiting lets the mud grab hold first. You can take it a step further and run the tape a little long past each end of the bead, gives you a tab to grab so you're not digging at the edge with your knife. On ceilings I'll sometimes tape both sides of the bead, not just the lip, so it can't rock while I'm pressing. Once it firms up the tape comes off clean and you barely see where it was. Ten extra seconds beats redoing a whole run.