If you want to sell gifts in your shop, you need to know how to tie a proper ribbon on a gift box. You want to look professional!
I remember my grandfather in his shop, teaching me. It took me quite a few attempts to get it right. Like so many things, it is easy to do once you get the hang of it. Note it would be best if you did it a few times as in retail you will need to be able to do it quick under pressure.
Your customers will often take it very seriously, so you need to do it right!
Here is a youtube that explains it very well a simple and good knot for you to start learning.