Take my favorite sewing notion: the magnetic dish. Time to toss the old plastic pin holder with the scratches and the crack and the falls-apart-every-time-it-falls feature. It's time to upgrade to this grease-monkey standby. Here's the standard metal version for the purist among us:
And a more exciting version in hot yellow so you can't miss it!
Look how strong these suckers are! I can even think of a few horizontal surfaces that could benefit from a magnetic holder this strong, like my ironing board.
My next favorite hardware store sewing notion are the heavy duty spring clamps. I use these to hold down material on the cutting board. Really helpful for straightening the grain. If I have a particularly bad piece of off-grain fabric (like a cheap muslin) I'll use several of them to clamp down each side and stretch the grain into submission. For well-behaved fabric, I use them to hold the salvage end while folding over the length for layout and cutting. 
I made good use of these handy small-hand sized wire cutters and pliers when taking Gertie's Bombshell dress class from craftsy.com:
They are small enough to easily snap each side of spiral steel boning (yup, they really do "spring" apart!). If you get big honking wire cutters you just don't have the dexterity to cut a single rung on the spiral steal. These do the trick.
And last but not least, a small box cutter is THE BOMB for ripping out stitches and cutting button holes. If it dulls just snap off a segment and you have a new sharp tool that works much better than a standard seam ripper. I even it to nip threads.
