I attended a quilt retreat recently where they hosted several demos. The first thing they showed us how to make was a triangle thread catcher.
I have no idea where the shop got this pattern, or if it's their own. I did a quick Google search through the vast Internet sea of tutorials and noticed there were plenty. Here's my addition to the Tutorial Sea:
Start by cutting out some 60 degree (equilateral) triangles—one for the outer fabric, one for the lining, and one out of batting. The larger the triangles, the bigger your thread catcher will be.
Layer the outer and inner fabrics right sides together, then place the batting on top. Sew around the perimeter, leaving an opening for turning.
Clip the points, turn the triangle right side out and press. Fold in the seam allowance at the opening and topstitch around the perimeter of the triangle to close it.
Bring two of the points together. Sew the side up from the bottom towards the points. How far up do you sew? I dunno. All I know is you want to be able to fold down the point later on and not have it touch the floor.
Repeat, sewing the other two sides. Stop at the same distance from the end.
Your triangle thread catcher now looks like this.
Use buttons to hold down each point and you’re done! Isn’t it adorable?