Always when anyone order fries from any fast foods restaurant, we find a difficulty on using ketchup pack. We used to to pour all of the ketchup over the fires or spread it on the fries one by one. In fact it is the wrong way.
This video shows the proper way on how to avoid messy ketchup-stained hands. The simple and easy way is to open the corner of the pack, just a small size to the fires to fit. Dip in your fries and you can just have enough ketchup that you want.