The templates for this project are all attached as JPEG images, CorelDraw files and SVG files. I've even added a PDF file for gmjhowe. Use whichever version you like to produce and print a copy on A4 copier paper or light cardstock.
You can colour the plain template with pencil crayons, sharpies, or whatever you like, or you can use your favourite graphics software to add texture to the template - woodgrain for the coffin, stone for the headstone.
Cut out both pieces along the solid outer lines.
Crease along all the dotted lines. Practice-fold the pieces into shape before gluing.
Glue the triangular tabs, and fold into shape - each tab glues under the next quadrilateral.