Paper cave: I think ceilings are underused for interior decorations. Would love to try some more colorful paper or plastic cones on our ceiling. At least in a small section. It would also be a great way to add too a "man cave".
butterfly garland What a great idea, and it would be very simple to do. All you need is a butterfly punch, and paper. Punch the shapes out of colored cardstock, fold wings away from body, and glue them back to back along the string. Couldn't be easier!
Michael Tompsett 'World Map - Paint Splashes' Canvas Wall Art - Beyond the Rack Final piece idea maybe. I like how it's has been done messy but then the stencils make it look very neat. It goes really well with the title.