Use 20 round papers or use a round punch to make 20 round papers.
You need to make an equilateral triangle on the circle (three points equidistant from each other). To do this fold the round paper in half and again vertical so you get a cross. Fold the bottom half up to the intersection of the cross.
The top edge where the fold is and the lower two fold points make up an equilateral triangle.
To create the flower ball you’ll need to fold 20 triangles, with the edges up. Glue the edges to each other, so that at each top 5 triangles come together. The easiest way to form the ball is to glue 2 sides (of 5 triangles) to each other and then fill up the other sides with the triangles so at each top 5 triangles come together.
Take a needle and make a small hole in 2 triangles so you can put a cord through.
With this flower balls you can make mobiles, garlands,.....be creative and have fun!