You know those little plastic sticks with foam on each end that we ladies use to apply eyeshadow? Well those little things are the best for cleaning the lint out from all around the bobbin area (after the bobbin has been removed :=) )
So I use that first. After using that, I sometimes go over again with my brush, and then to top it all off, I use my little vacuum. Those pieces of lint are pesky little things! I do this every time I have to change the bobbin.