Clearly Perfect Angles
The Clearly Perfect Angles (CPA) by New Leaf Designs will be the most practical notion you've ever used!
It "clings" to smooth sewing surfaces (no taping) so it's always in position ready to sew ANY 45-degree angle accurately. There is a Fabric Alignment Key and 1/4" & 5/8" seam guides. It's also color-coded for different techniques. And it does not need to be removed to access your bobbin or move your table!