Fellas, your side of the closet might be no bigger than your first-grade cubbyhole. Or maybe you have a spacious man cave of a closet that stands as a shrine to your varsity football years.

No matter how much space you’re working with, a clean and organized closet is a happy closet — which means no blaming the dog for a mysteriously missing shoe and no accidentally wearing a button-up shirt with a stubborn grease stain to an important client meeting.

Here are some expert tips for getting your space in order — without spending big bucks on a whole new closet system.

Take an honest assessment of what you have: Have you heard of the 20-80 rule? People tend to wear about 20 percent of the clothes they own 80 percent of the time, says Barry Izsak, a certified professional organizer (www.arrangingitall.com).

When to say goodbye

Izsak’s rule of thumb: If you haven’t worn something in two years or keep saying you’ll take it to get repaired or fix the zipper, it’s time to part with the item.

“Saving that stuff that you think will come back into style is never a good idea,” he says. “The problem is when paisley comes back in style, the width of the tie is going to be different.”

If you have some items that you’re iffy on and not sure whether you want to keep them, turn their hangers backwards and, as you wear the items, turn the hangers back around so they are consistent with the rest of your closet, suggests Izsak, who is past president of the National Association of Professional Organizers.

Certified Professional Organizer Lorie Marrero, creator of the Clutter Diet (www.clutterdiet.com) and a spokeswoman for Goodwill Industries International, suggests getting an objective second opinion when tackling a closet clean-out.

One of the challenges with men’s clothing is the styles tend to be more classic — meaning guys hold on to the styles for longer. When deciding if it’s time to get rid of a shirt or pair of pants, take a look at the wear and tear, as well as the fit, she suggests.

Space game

Rather than consider closet reorganization a burden, it’s more fun to think of your project as a game of Tetris — fitting the pieces just right and, thus, maximizing space.

“It doesn’t have to cost a lot of money to redo your closet,” Izsak says.

He suggests checking out big-box stores for storage solutions and space savers.

“One thing we encourage is that if you’re short on hanging space, consider folding things — like T-shirts or polo shirts,” he says. “Vice versa, if you don’t have the drawer space, then start hanging the things you would fold.”

If your closet has just one long hanging rod, get a second bar so that you can take advantage of a double hang, Izsak suggests.

Because men’s shoes are typically more bulky and cumbersome than women’s, Marrero suggests avoiding shoe shelving units with cubby cubes because they usually only fit one men’s sized shoe per cubby.

Use A, B, C, D space

One of Marrero’s favorite strategies is to look at the frequency of use of each item — you could be taking up some valuable closet real estate with items you’re not using.

“A” items are things that get daily use — like socks and underwear — and should be the most accessible, she says. Items in the “B” category you wear often, like general everyday shirts. They can go in drawers that are a little higher or lower.

Seasonal items such as a Christmas sweater are “C” type items and should be up on a high shelf and out of the way, Marrero says. And “D” type items are items you’re not using, but that are sentimental — think your high school letter jacket — and should be stored away.

Donate to the thrift store

Marrero, also an ambassador for Goodwill’s Donate Movement (donate.goodwill.org), says that in general, Goodwill takes gently used clothing for resale and it’s always helpful if you can bring those items in washed.

However, if you have torn, ripped or stained clothes, or used socks, for example, you can put those items in a separate bag labeled “salvage” so it will go into Goodwill’s salvage and recycling program.

And be sure to track the value of your donations for your charitable deductions come tax season.