Crafting leather should be easy. And it is if you have a piece of excellent leather and a good construction.
We have that. Then it is just to cut the leather into its construction pieces and sew or glue them together. For that you need a needle (or sewing machine) and some white thread or glue.
However, improvements can be achieved through a lot of training, experience, patience and time. To know when it is better to punch out pieces rather than cutting by hand with a knife. To know when the sewing machine will sew more beautiful stitches than by hand with a needle. To know a lot of things.
One example concerns the edges of our Briefcases. We don’t like to thin our leather, and we never thin it to be able to wrap it around the edges, which seems to be the standard practise nowadays. We rather leave the edges of the two layers of spruce bark tanned Swedish cattle hide and Nordic reindeer skin visible. However, they also become exposed to the surroundings. Therefore, we colour the edges of the Briefcase to protect and strengthen them. We do this by hand in a simple process that includes polishing and colouring. This needs to be repeated several times. How many times depends. Only from experience you will know how many times is enough.