To paint over ANY surface, without sanding, use a product called 'ESP Easy Surface Prep', available at hardware and paint shops. Wipe on, wipe off and paint in 90 minutes. Works well over enamel paint , without having to sand. SAVES HOURS of work. It was recommended to me by a professional painter.
Use Crates as Shelves. Paint and pretty up ... leave them natural... your choice. Add some brackets to wall , put your Storage Crate on the Brackets and ... Voila ... Shelves !! Would be awesome for documentation that includes artifacts!
Mason jar air freshener - fill a small mason jar about 1/4 full with baking soda, and add 6-8 drops of your favorite essential oil. Punch holes in the lid, and place in any spot that could use some freshening. Every once in a while, give the jar a gentle shake to boost it's air freshening power.