Keep your filling knife clean
I’m no expert when it comes to DIY. Enthusiastic amateur I’d say. I fumble my way along, guessing how things should be done, and generally learn the hard way. I needed to do some more filling today to plug the holes I’d left from my poor skirting board fitting skills. My filling knife however was caked in gunk after a few years of not being cleaned properly. I kept it clean when I first got it, it was new and I took good care of it....