Artangel: Mixed media crumpled tissue technique - tutorial - basically, glue tissue paper over a canvas, let dry. Paint, let dry, then rub pastel or chalk over the surface to highlight the texture. Would be an awesome way to vignette around a painting.
This Canvas String Art Graffiti project is fun for kids and adults alike. While this is a spray paint project, you can use alternative paints or dyes for younger children. Makes a fun summer art project when your kids get bored.