I’m torn between whether to call this look Checkmate, or Squares Squared. Either way, you get the idea. You take one checked piece of clothing and add another. Fashion maths often has a skewed geometry all of its own and this is one of those moments. Adding check on top of check has the opposite effect from the one you would imagine. One checked piece looks sensible and straight-faced. This blazer, for example, bought a few years ago from Topshop, looks responsible-but-not-totally-boring when I wear it with a midi-length dress; this tartan blouse from Rag & Bone is an old favourite for the shot of instant energy it will add to a pair of black trousers. But two checked pieces looks surprising. When I wear these together, the tone shifts from workmanlike to positively woo-woo.

A similar thing happens when you pile up florals: two or more pieces is far less pretty, less tame, than one. Checks have been happening in fashion for a few seasons and, this autumn, the check-on-check trend was everywhere. At Chanel, woollen coats in oversized windowpane checks were layered over houndstooth tweed trouser suits for a look that was both dapper and flamboyant. At Victoria Beckham, a muted checked wool blazer and a softly checked shirt – either of which would have looked like traditional, understated, English-country-weekend chic on their own – made an eyecatching ensemble worn together, and styled with a crossbody bag and highlighter-neon court shoes.

You don’t need to stop at two. These snake boots I’m wearing are almost a check, too – the same graphic crosshatching, but in a squiggly, reptilian kind of way. Check on check on check? The more the merrier.

The capriciousness of fashion maths is an advantage when it comes to shopping what is already in your wardrobe. If you liked a trend when it was all over the shops – whether it was checks or florals, or fuchsia pink or leopard print – then perhaps, in your enthusiasm, you over-shopped. It’s worth revisiting those pieces, to see where you can layer up – a checked blazer over a checked shirt, or a floral dress with floral ankle boots – to breathe new life into them.

They are there for a reason, after all. If you keep going back to a certain pattern or colour, it must be because you like it. Who said you can have too much of a good thing?

• Blazer and blouse, Jess’s own. Skirt, £39, oasis-stores.com. Boots, £190, dunelondon.com. Styling: Melanie Wilkinson. Hair and makeup: Samantha Cooper at Carol Hayes Management using Mac Cosmetics and OUAI.