I'm installing drywall for the first time and am having difficulties with inside corners. I used the paper-faced metal inside corner bead and managed to get it embedded nicely. The second coat went fairly smoothly, but now I'm having great difficulty getting that third coat perfect. Every time I drag the knife down the corner, I always mess up the other corner. I've tried a corner knife, but haven't had much luck with it. I'm also aware that you can do one corner at a time, but when I tried it, I still found I was messing up the other corner with that approach as well. Any tips or tricks would be most appreciated! Thanks, Cameron.