For Ryan Knolls, the busiest days of the year are the day before Thanksgiving and the eve of Christmas Eve. That’s when business doubles for TidyCasa, the Scottsdale-based house cleaning service he started almost 10 years ago.

“The pre-holiday cleaning overdrive is real,” said Knolls. “We get panicked callers. They’re freaking out about their homes not being guest ready. They say, ‘I’m hosting everyone for dinner and want the house pristine.’”

Call it the clean before the storm.

“People are already overscheduled, and now they’re worried that their company will think they’re slobs,” he said. Knolls has been there. He remembers doubling down on his own cleaning before holidays. “It wasn’t how I wanted to spend my time off.”

Regardless of whether you clean your house yourself or hire help, most homes follow an 80/20 rule, Knolls said. We do 80 percent of the housekeeping regularly — tidy, sweep, mop, vacuum, dust, wipe counters and clean bathrooms.

But that remaining 20 percent is what makes a house feel immaculate — and it should be tackled twice a year, he said. Spring is one of those times. The other is right now, before the holidays hit.

You want people to walk in and say, “Why does this place smell so good?”

Here are the top 10 tasks on that 20-percent task list:

1. Hit the high stuff. Grab an extending pole, one of Knoll’s favorite tools, and dust off the dust bunnies lurking on top of cabinets, draperies, high shelves, light fixtures and AC vents. These are all common areas of neglect, Knoll said. Knock the dust to the floor, then sweep and vacuum.

2. Wipe down baseboards. Another of Knoll’s favorite tools is a Baseboard Buddy (available on Amazon for $25). It’s an extending pole with a swivel head that holds a microfiber pad. It works on high moldings, too.

3. Give rugs a shake. Carpets are a home’s No.1 dirt trap and need thorough regular vacuuming. When deep cleaning, however, you need to roll them up, take them outside and shake them hard. Clean the floor under the rugs, then replace the rug and vacuum thoroughly.

4. Wash the windows. Clean not only the glass windowpanes inside and out but also vacuum and wipe the tracks and sills, so they’re fee of insect carcasses and dirt. Windows will look and work better.

5. Deal with drains. “If you think your bathroom smells funky, and you don’t know why, it’s almost always the drains,” Knoll said. Another tool he likes, also available on Amazon ($33), is the Drain Weasel, an 18-inch flexible stick with a screw-like tip designed to grab hair, gunk and whatever else clogs your sinks, showers and tubs. Push it in and yank it out. You might be surprised what you fish out. Rinse with a very small amount of bleach or an enzyme-based cleaner and rinse well. Then notice how much fresher your bathroom smells.

6. Get the boogieman under the bed. The area under the bed and other furniture gets ignored, but it’s a total dust and fuzz trap. Left uncleaned, these spots can make the whole room smell musty. Twice a year, get under there with a vacuum.

7. Clean range hoods and ovens. Since friends and family will likely be in the kitchen, make sure yours is de-grimed and degreased, especially often ignored appliances like your range hood and oven. Tip: If your oven has a self-clean feature, don’t run it the day before you’re roasting the turkey. Occasionally, the extreme temperature needed to clean an oven can make it stop working. You don’t want to spend Thanksgiving morning panic-dialing appliance repair.

8. Buff drawers and doors. Cabinet fronts are another often-forgotten surface. “We wipe floors and counters, but overlook cabinet and drawer fronts, which slowly get coated with dust and grime,” Knolls said. Microfiber cloths are great for this job.

9. Clean the shower curtain. If you don’t do this a couple times a year, the liner gets a coating of funk. But cleaning these is easy. Take the liner down, soak it in the tub with cool or lukewarm water and a little Dawn detergent, scrub it with a bristle brush and hang it back up to dry.

10. Refresh silk plants and flowers. Even though you bought them because they were low maintenance, silk plants and flowers still need some attention. Dusty leaves are a dead giveaway that these plants are not alive. Spray them down now and then.

Although a clean house now may help you relax and enjoy the holidays more later, don’t obsess, says Knoll. “Do what cleaning you can, then make the focus on spending time with others.”

Marni Jameson is the author of “Downsizing the Family Home” and other books. Reach her at marni@marnijameson.com.