With the following decorations (ornaments) it’s almost hard to imagine that they are carved from stone. Carving stone is tremendous hard labor! Some though look like feathers or leaves.
Exercise 1: To draw this first symmetrical decoration it’s best to start with the two construction lines (drawn here in red for clarity): one through the center and one for the outline of the leaves or feathers . Then you can fill in the details and color the decoration.
Exercise 2: The next classic corner ornament almost looks like an animal. Also try to copy this decoration. Start with the S-like shape with the curled ends.
In the horizontal strip at the bottom of the decoration a Meander motif is drawn. The name Meander comes from a strongly winding river in Turkey. Do you recognize that winding in the motif ? There’s also a wavy version of it (next image).
Exercise 3: Draw the Meander motif, straight and/or wavy.