It is a recommended practice to hold the scissors in your weaker hand in the middle of the cutting edges. Consider placing the ring finger of your side into the top opening and put your little finger on the pinkie rest that can be seen on the outside of the opening. You should use your ring finger on the opening in a way that the ring of locks goes around the finger.
Now place your thumb into the end opening so that the top of your thumb is in contact with the top-inside part of the opening. The band should go around your thumb about 1/4 inches below the bottom part of the thumbnail.
Now join your middle finger and index together and place them right under your band finger. Based on the scissors you will be using, there may even be a minor pattern in them. That is where your fingertips are meant to be placed.
Finally, you will need to place your middle and index finger of your right hand below the edges. This should be done in a way that the bottom blades are placed on the two fingers. Blades can be closed or opened using only your thumb. This is the proper way of cutting hair using scissors.