My all time favorite notion is "The Cutting Gizmo" from
www.thegypsyquilter.com. It stand about 6" high and is plastic. In the middle at the top is a razor. This is for strip sewing. After I've done all my strip sewing, I lower the threads between the fabric pieces and it slices the threads apart. Perfect. I don't have to get out scissors or a rotary cutter. I put it to the left of my sewing machine and just turn my chair when I'm done sewing and cut them all apart. It's saves so much time.