Prepare two pieces of leather (about 6 cm width x 11 cm) and a piece of leather (about 6 cm width x 21 cm) and two sets of Spring Snap Fastener.
If you want to use it as a pen stand, etc., make a round hole like as shown in the image.
Here we use the LeatherCraftTools.com kit "Leather Multipurpose Stand Kit".

Finish the split side and edge of the top part.

Use the Spring Snap Setter Small to attach the male parts of the Spring Snap Fastener to the bottom part.

Glue the bottom parts with the split side of each other together.

Finish the edge of the bottom parts.

Sew the side of the bottom parts as shown in the image.

Trace the stitch line.

Attach and glue only one end of the top part to the bottom parts and sew as shown in the image.

Referring to the stitch position image, fold the top part to make the small ridge and sew as shown in the image.

Use the Spring Snap Setter Small to attach the female parts of the Spring Snap Fastener to the top part, then it is done.

Fasten the Spring Snap Fasteners when you use it as a pen holder, smartphone stand, etc.