Whether you're heading to Europe for a city break or planning lazy days on the beach, shopping for a holiday should be stress-free – just streamline your wardrobe, says Harriet Walker. Styling by Gemma Hayward

The spring/summer season often feels like a bit of a blur.

One minute, you're contemplating a sundress while it's still snowing outside; the next, you're shopping for your beach holiday and all you can find is duffel coats. That's why now is the perfect time to shop for your holiday, the last chance before the sales kick in; and the early autumn pieces have started arriving too, so you can blend a look that is at once summery and holiday-ready, but which has a slightly longer shelf-life to see you through to the very end of the season.

The phrase "summer essentials" seems to instil in many people a great sense of fear – the distillation of one's personal style into a few select garments can be very difficult. Roughly speaking, the trick is to rely on separates and accessories to do the styling for you; keep your main pieces basic and liven them up with scarves, hats, belts and jewellery.

You can't go wrong with denim, for example, whether it's a pair of shorts or an over-sized shirt you can throw on over a T-shirt or sundress. Likewise, there's a reason why the staff at French Vogue each own several thousand Breton tops and striped dresses: it's a style that can be nonchalant and off-duty, but add a jersey blazer and some statement sandals and it's a look that will work in the evening as well. Try also to pick out one more fashion-y piece for your suitcase, whether a printed dress or a top that will work for evenings or formal occasions. You can always dress it down with a blouse – in one of this season's prominent neutral or putty-ish shades, of course – or throw on a sun hat for daytime.

Gap's Basic Tees in tri-blend grey marl, beige and white are perfect for layering and pulling on with shorts and skirts, and jersey pieces are terribly au courant; try out a maxi skirt or dress if you dare, but be sure to keep the silhouette lean and colours sober. You can spice up these essentials to whatever degree you're comfortable by adding a digital print scarf or a chunky cuff. Pack one extra vest with a little more detail just in case you reach that point where chic basics start to feel too samey: Acne's ruffled version is just the thing.

Finishing touches should be quiet and functional – H&M's baggy shirt is perfect with shorts, or worn as a cover-up when the sun goes in. A hat is a must if you're in the sun (no one likes a burnt nose) and, although The Independent fashion desk would never suggest wearing a trilby in real life, we'll happily endorse All Saints' super-cool bleached version, with its minimal leather trim.

As with so many fashion ironies, it takes a lot of effort to look perfectly off-duty. But if you get it right, you really can relax and enjoy yourself on your holidays.