This isn't in English but one can see how it's done from the illustrations... looks to be totes upcycled from T-shirts or other sleeveless tops. Cute fabrics! And they're lined. Could be nice gift for a teacher.
Flowers from felt...
Sew Simple Patterns | Housewives
Make these cool flowers with interlocking Ric Rac~
DIY Rose from Crepe Paper http://www.usefuldiy.com/diy-rose-from-crepe-paper/