Take the cardboard backing from any A4 style notepad. Measure out your feet, the width of the pencil if enough of a distance to use.

Cut out the shapes, it doesn't matter if they are not perfect. If you want you can make 2 sets for each flipper, to make them thicker. I didn't.

Take your fabric you are using to line the flipper and measure out each individual piece, cut out and pin to the cardboard flipper.

Sew the liner to the cardboard flipper, be careful as I broke my needle by moving the cardboard too much! doh

*If you have made 2 sets of cardboard for each flipper, you can glue the second cardboard piece to the first one after you have sewn the liner and band on

Measure the fabric you are going to use for the band across the top of your foot. I used doubled over felt.
Sew any edges of the band you need to before adding to flipper.

Attach the band to the flipper, I machine sewed it on.
You may want to try the band on your foot and then pin it in place, just to make sure you are giving yourself enough room.

*If you have made 2 sets of cardboard for each flipper, you can glue the second cardboard piece to the first one after you have sewn the liner and band on

Add any embellishments you like or leave it plain, whatever :D

Wear and enjoy.

If I was to make them again, I would avoid sweater fabric, it just stretched and moved all over the place when I was sewing it. Also I would go for adding the two layers of cardboard flippers :D