I use the magnetic hooks to hold up my rulers on the metal cabinets in the garage or a stencil template I am using on quilt so easy access and i don't have to search around for it.
I use a 12" square mirro for under the longarm to see how the quilting is going and I do not have to roll the fabric up and one of those hallogen shop lights my husband sells so I have light to look under the longarm as well as in my machine to clean it and for the domestic machine to see the details I need and clean it up. The light has a magnet on the back so i can attach it to the metal frame of the sewing machine so I can have a close light on things when sewing, ripping, or need to just see. i steel this stuff from his stash. Also, his allen wrenches, screw drivers, and the plastic screw bins so I can organize my threads, needles, buttons, and spools. Works terrific. Also themagnetic screw tins, have two sizes so I can put different pins in each one. Then the L ruler from his tools, works terrific for squaring up blocks and to set a line for pantos on longarm. Then the binder clips to hold the tape measure in place on longarm frame. The strong magnets to hold quilt on metal frame. just saw this thread so thought I would add a couple things I use.