My love affair with vintage fashion began early in my teens, when I would spend my Saturdays scouring charity shops in Belfast for 1960s psychedelic prints, 1970s boots, faux fur jackets, and anything batwing or mohair (or Escada) from the 1980s. As with many thrifting obsessives, a relationship that was born out of crude necessity (where else but a charity shop could a 14-year-old score an entire outfit for $20?) evolved into something much more meaningful. I learned to respect the workmanship and quality of beautifully tailored Irish tweed, French silk, and Scottish cashmere; I admired the boldness of the silhouettes and gutsiness of the prints, forcing the rest of my outfit into submission around that solitary standout piece. Eventually came the classic hallmarks of a long-term love affair: I’d feel a little pang when I’d catch a glimpse of a care tag from the '70s, or a dated designer label font, as lovers do about misshaped earlobes, a familiar navel, or crooked little finger.Ever since I got serious about vintage fashion, I adhered to one strict rule: not mixing and matching my eras in a single outfit. I would regularly pair a thrifted piece with contemporary items of clothing — perhaps a secondhand suede jacket with a Reformation dress and Isabel Marant boots, or a gold shift minidress from the '60s with Tods penny loafers. But combining different decades? I was convinced that was the sartorial equivalent of pouring gin and whiskey into the same cocktail.Rebecca Rose, of cult high-end vintage boutique Juno Says Hello , says: “As a general rule, mixing different decades in the same outfit can be quite hard to pull off, because the silhouettes vary so much throughout the decades. Clashes are almost inevitable.” And I agree. But a recent extended stay in L.A., with a badly packed suitcase stashed full of vintage treasures I was too sentimental to leave behind in favor of sensible "neutrals," "basics," and "classics" (yawn), forced me to rethink this rule. It made me realize that decades are just labels, man, and you can mix items from different eras — as long as they work together thematically. I found, for example, that my nearly-five-decade-old Lee kick flares work beautifully with my even older red felt cape. I worried this would look too, well, "flarey," but somehow the silhouettes meshed, echoing each other in harmony.Mixing and matching vintage eras definitely takes vintage dressing to the extreme; it’s not one for retro newbies, or anyone who dislikes being mocked by teenage boys in the street. “Mixing decades for a multi-generational fashion look often veers on costume or too editorial,” says fashion historian Cameron Silver , founder of Decades in L.A., and fashion director of H by Halston and H Halston. “If you're an authentic eccentric, it’s an option. But generally, I would say choose a decade and stick with it.”But since rules are made for breaking — particularly those that pertain to fashion — in place of my "no mixed vintages" rule, I’ve come up with slightly more forgiving guidelines: Allow one vintage piece to be the star of the show, and the others to be back-up singers; think the Supremes to Diana Ross. Use revivals wisely: The 1970s saw a 1950s revival (Grease landed in cinemas in 1978), so you can pair key pieces — plaids, capes, poodle skirts — from the same era. (Similarly the '90s saw a '70s revival, hence why platform heels work so beautifully with flared denim.) But the most important rule of all? Try it on, and see if it works. And if you feel like two statement pieces are shouting over each other, it’s only polite to separate them. “Vintage is usually your conversation piece,” says Silver. “When one mixes up too many conversation pieces, things get noisy.”If you're up for a challenge or keen to give this a whirl, start with one of these five multi-generational multi-taskers to get the ball rolling: