Printing Ink for my printer - I use it for labels.
Scotch tape - when I take a screw out of somewhere, I tape it to the machine either in the hole or beside it so it doesn't get lost.
My handy dandy multi tip stubby screwdriver. I can't hold onto the tiny things that come with the machine.
And a roll of stick on, dry erase board. I cut a piece to fit the door of my armoire beside the sewing machine. If I have to remember #'s or sizes, I write them there.