Kitchen
Stove hood filter that smells like old fryer oil
You have: baking soda, white vinegar, a big pot you do not mind getting hot water in.
The combo: Soak the metal filter in a pot of hot water with a half-cup of baking soda and a cup of vinegar. The fizz loosens the greasy film. After thirty minutes, scrub with an old toothbrush and rinse.
Do not boil the vinegar. Hot tap water is plenty. Boiling makes the smell stronger without cleaning better.
Bathroom
Shower door with hard-water spots
You have: white vinegar, dish soap, a microfiber cloth or an old cotton t-shirt.
The combo: Mix equal parts vinegar and dish soap in a spray bottle or bowl. Apply to the glass, wait five minutes, then wipe with the cloth. The soap keeps the vinegar in contact with the glass long enough to dissolve the mineral buildup.
Skip this on natural stone. Vinex will dull marble, granite, and travertine.
Workshop
Stripped screw that will not budge
You have: a rubber band, a screwdriver that almost fits, and a little patience.
The combo: Lay the rubber band flat over the screw head, then press the screwdriver down through it. The rubber fills the gap between the tool and the damaged head and gives you enough grip to turn it slowly.
Use a wide band. Narrow bands tear under pressure and leave you worse off than before.