Construction theme: Geometric LEGO Blueprints: A STEAM activity for Kids. Combine Math, Art and Engineering for a hands-on activity that is fun and engaging.
Roundup post with lots of fun Montessori-inspired construction activities for preschoolers. Would leave out the "hide the vegetables" montessori aspect though.
Wesley Summer Painting with truck fun mark making and messy play idea for toddlers from the book Goodnight Goodnight Construction Site.
Spatial and number skill development