Extension cords are temporary helpers, not the cure for your old-house lack-of-outlet blues. Placed on the Consumer Product Safety Commission's Substantial Hazard List in 2015, some cords—especially the no-label, dollar-store variety—prompt constant recalls that cite electrocution and fire risk.
INSTEAD: Throw away old extension cords and any with loose plugs, split casings, or cheap-looking construction. Don't run cords under rugs or around furniture, as they can overheat or crack, sparking danger. Use the right cord for the job: a 16-gauge cord to power small household appliances, such as a fan, that draw up to 13 amps; a 14-gauge cord for large power tools, like a table saw, that use up to 15 amps; a 12-gauge cord for items that need 20 amps, such as a compressor. And consider upgrading to grounded receptacles where you need them most.

10 | Storing Stuff in an Over-the-Showerhead Caddy
Your morning refuge may need more perching places for shampoo and body-wash bottles, but a showerhead storage unit loaded with containers will stress the threaded connection behind the tiled wall, potentially causing leaks.
INSTEAD: Store jumbo bottles on the shower floor or tub surround. For lighter stuff, try shelves that attach with suction cups. Got a whole family's worth of bottles and soaps? Stick them on an over-the-shower-door caddy, which can hold about 10 pounds.

11 | Tossing Bleach Tablets in the Toilet Tank
Those handy blue toilet-tank blocks will keep the water fresh and the bowl clean —and cause premature brittleness or breakage to the flapper valve and other rubber and plastic parts.
INSTEAD: Go old-school with a toilet brush and an occasional dose of cleaner, or use a flush-by-flush product that puts the cleaner in the bowl, not the tank.

12 | Straining Circuits
With a "click, click" you might get the toaster browning bagels again, but repeatedly resetting tripping breakers is bad practice. Too many clicks can cause the safety mechanism to wear out, increasing the risk of an electrical fire.
INSTEAD: Unburden the breaker by running fewer items on the circuit. "Dehumidifiers, countertop convection ovens and microwaves, and air conditioners are often overload culprits," says master electrician Scott Caron. He suggests having an electrician replace a breaker that's tripped five times, and, for a long-term fix, upgrading the entire circuit to handle a higher load.

13 | Scrubbing Grout With Vinegar
If you, your jug of Heinz, and that old toothbrush are rendezvousing regularly with the bathroom grout, look out. Traditional white grout is a sand-and-cement mix; that cement is an alkaline compound and the acid in vinegar turns it yellow and crumbly.
INSTEAD: Choose a traditional alkaline hard-surface cleaner, like Spic and Span, or an oxygen-bleach-based one. Always rinse well; and to really lift dirt up and out, try a few passes of your utility vac to dry it.

14 | Closing Vents
Shutting the louvers on grills to force conditioned air to go where you want it might help control the temp in a room, but it causes a pressure imbalance in the ducts that can make the furnace work harder or the cooling coil freeze over.
INSTEAD: Have an HVAC contractor install branch dampers in the main runs of your ductwork. Use them seasonally to force cooler air to the second floor in summer and warmer air to the ground floor in winter.

15 | Mislubing Locks
A quick spritz with an all-purpose spray will improve the movement of most stubborn locks, but it won't provide long-term lubrication, which is why your rough-turning-key problem always seems to return.
INSTEAD: Your handy can of multi-lube is a quick answer for cleaning, de-rusting, and chasing condensation from inside the lock, but it's only the first step. After loosening a crotchety cylinder, latch, or dead bolt, use a silicone spray or a squeeze of graphite powder for lasting lubrication. Never apply household oil, which attracts dirt and can lead to an even greater gunk issue.

16 | Not Grounding a 'Cheater' Plug
Those orange or gray three-prong/two-prong adapters are handy when only two-slot outlets are available, but using them lazily by bending or breaking off the grounding tab results in an ungrounded connection and raises the danger of shocks or fire.
INSTEAD: Make sure that your two-prong outlet is a grounded one. A three/two adapter's wire or metal tab should be connected to the screw in the outlet's cover plate to ground the plug. Long- term, consider installing three-prong outlets housewide, if wiring allows.

17 | Using Drywall Screws for Everything
You risk having upper cabinets, open shelving, or even heavy mirrors come crashing down if they are hung with fasteners that are too brittle. Hardened-steel drywall screws break under heavy loads where other screws flex.
INSTEAD: Keep a variety of wood, cabinet, and deck screws on hand so that you're always prepared with the right fastener for the job. Wall cabinets will have ample holding power if you drive two 2½-inch (you guessed it) cabinet screws, with washers, through cabinet backs and into wall studs—never, ever into drywall alone.

18 | Hanging Dry Cleaning on a Doorknob
Four pairs of pants and eight shirts might weigh 8½ pounds. Hooking that load of dry cleaning on a door handle every week can strain the knob and even the hinges, pulling the door out of alignment.
INSTEAD: Walk directly to closet upon entering. Open door and hang dry cleaning on properly mounted closet rod (see No. 1). Repeat. Every week.

Taking a can of paint back to the store for a spin on the shaker is fine. Stirring paint with a drill attachment, or even extensively by hand? Not recommended. "You'll create air bubbles that stay in the paint and leave thin spots in the finish," says John Calderaio of the Paint Quality Institute. "Overmixing also creates grit," he adds, "by making paint molecules clump together."
INSTEAD: Stir slowly and gently with a regular old wood paint-stirring stick. You'll know you're done when there are no solids at the bottom of the can and an even, uniform stream of paint dribbles off the stirrer.

20 | Overdoing Drain Cleaner
Serial doses of clog-dissolving liquids or crystals containing sulfuric or hydrochloric acid or lye—even those that say "septic safe"—can wipe out the essential bacteria that break down waste in a healthy septic system.
INSTEAD: As a first line of attack against a clogged drain, flush with boiling water. For stubborn clogs, a routine mechanical cleaning with a closet auger snake is less damaging than those drain-clearing chemicals, which should be used only if necessary, and then only sparingly.

21 | Letting Receptacles Rock
Electrical outlets can loosen over time, especially heavily used ones, like those on a kitchen backsplash or where you usually plug in the vacuum. That wiggle can cause the wires to pull out, increasing the chances of arcing—and fire.
INSTEAD: Turn off the power to any loose outlet at the electrical panel. Unscrew and remove the outlet cover, tighten loose wires, and use plastic shims to stabilize the receptacle's "ears" before putting the plate back on.

22 | Stressing Trusses
A 4-by-8-foot sheet of ¾-inch plywood weighs 71 pounds. Balancing a few of them, along with stray 2×4s, wainscoting scraps, and a bundle of shingles up in that open space above your head can tax garage and attic trusses, causing them to bow—or maybe collapse. Even a traditionally framed roof, which is stronger, can fail if overloaded above the joists.
INSTEAD: Store heavy materials where they won't need to defy gravity; leaning plywood against a garage wall is one space-saving solution. Take advantage of the dead space in corners by installing a triangle shelf to keep things like roofing shingles flat. To make one, bolt a pair of 2×6 ledgers to the wall, then screw on a ¾-inch-thick plywood pie-slice wedge. Concerned your trusses could be compromised? A structural engineer can tell for sure. Tom Silva suggests strengthening joists or a weakened ridge beam from underneath using engineered wood.

23 | Painting Over Rust
Slapping a coat of paint over metal that still shows signs of rust is a temporary cover, but not a fix. The iron oxide will prevent the new paint from grabbing hold, so sooner rather than later the bond will fail and flaking will begin.
INSTEAD: To properly coat rusty railings and metal furniture, use a scraper to remove surface corrosion and peeling paint, feathering paint edges with 100- grit sandpaper. Treat spots with a rust primer before coating the whole thing with direct-to-metal (DTM) paint, a special acrylic formulation.

24 | Fertilizer Overspray

We know: You're just trying to feed your lawn's every last hungry blade. But fertilizers that contain sulfates or ammonias can chemically react with the cement in concrete, wrecking a walkway, damaging a driveway, and even causing cracks in your home's foundation.
INSTEAD: Stick to fertilizers with synthetic urea as their nitrogen source—unlike ammonium nitrate, it won't damage concrete. If your product contains ammonia, keep granules at least 6 inches from concrete surfaces. And use a broom, not a hose, to corral rogue pellets, since water activates the harmful compounds.

25 | Using the Provided Wall Anchors
Assuming you can rely on those expanding blue plugs that come in the package with the picture ledge or window shade or towel bar just doesn't cut it. These ubiquitous sheaths are designed for dense masonry and plaster walls where they can grab onto holes in the material; if you're sinking them into drywall, which is more likely, the material around them will eventually crumble.

INSTEAD: Drywall calls for an anchor that can grab the thin wallboard and hold a screw. Choose a threaded anchor and an appropriate fastener that is twice as long as the material is thick. Toggle bolts are another good choice and not nearly as combative as they look.