I usually skim fat off top with a ladle after it's cooled a little. Only way I can do it. I add little water to flour I've sifted. I have an old Tupperware shaker I put the mixture into. When I get ready to pour the mix into the pan of juices I grab the sifter again and pour it through that. Catches the lumps. Once in awhile, I'll make a roux then add water or broth. Today is the first day I'm doing a pork roast in a slow cooker. Been decades and not sure why Ididn't do it sooner. We'll see what happens.