3D Chalk Hole

Hi There- I think my last comment didn't upload so doing this again- if I'm just not seeing it, I apologize if it's a repeat....  I am the event organizer of a Chalk Festival at my child's elementary school.  It's our 5th year running and has become an event everyone looks forward to!  All students participate and even the principal does his own art piece.  He always picks something fun and this year he wants to try and replicate this drawing (3Dbricks.)   Would you mind giving me a few tips, in terms of planning and execution, for me to pass along to him?  Anything would be really helpful.  Thanks so much!