Empty prescription bottles for bobbins.
Those little silica packets that come in vitamin bottles and in new shoes and new purses. I put them in drawers with my fabric to absorb moisture.
Skirt hangers to hold finished small projects like wall hangings and table runners in my closet- no fold lines!
Pants hangers to hold long yardage in my closet- just fold over the hangers.
4 foot x 8 foot vinyl lattice (like for climbing vines) mounted on the wall holds all my quilting stencils. I use small S-hooks on it and wow, it holds hundreds of stencils.
Coffee filters to hold thread snips and lil junk on the sewing table and on the longarm machine.
Small paintbrushes to clean the bobbin area on sewing machine and longarm, and bigger paintbrushes to clean the rails on the longarm frame.
School chalk for marking, and the cheaper the halk, the easier it brushes off. I like the Dollar store chalk.
Batting scraps for brushing off the school chalk markings.
Clear plastic sheet protectors and dry erase markers from Staples. I take a photo of my quilt and a photo of my block, closeup. Put the prints of the photographs in the plastic sheet protectors, and then draw quilting designs on them with dry erase marker. I erase the designs with batting scraps. I just keep auditioning different quilting designs until I find what I like the best.