So if youre looking for a project that is interesting but low-cost then youre on the right track.
This clever idea is fromART Thao162on YouTube.
Mark 4cm distance on each side then make a line connecting it to the top curve.

Image Credit: ART Thao162 via YouTube
Use this pattern on the denim and cut it out.
Place the smaller shoe pattern on top, mark the outline, and cut.
Make two of these with the same pattern.

Take the other part of the padded fabric and cut out two more pieces of the curved pattern.
Insert the padded cut out under the fold of the denim, secure together using hot glue.
Mark crossed diagonal lines at 1cm thick.

Step 3
Using the bigger shoe pattern, cut out a pair of denim.
Draw crossed diagonal lines at 1cm thick.
Sew the line pattern on the denim sole and the curve denim.
Step 4
Cut a patterned/printed fabric 4cm wide, this will cover the edges of the slippers.
Fold it in half lengthwise, press, fold it again then press.
Insert the edges of the slipper between the fold, clip in place then sew.