The concept of a capsule wardrobe has been well and truly hammered home, and many of us try to invest in key, workhouse pieces that will see us from season to season. 

But what about the lingerie underneath our wardrobes, which provide structure and shape over which our clothes hang? It makes sense that applying the same mindset to our lingerie picks would enable us to make the best out of our clothes and feel our best too.

I'm a sucker for buying the same kind of bra every time I'm shopping, and then panic when I discover that I don't have anything suitable to wear under an evening dress.

With that in mind I was excited to hear what Roslyn Ellis, Brown Thomas's group buyer of lingerie, swimwear and hosiery, would choose as her essential 'capsule lingerie wardrobe' picks.

Speaking at the launch of Brown Thomas' new lingerie room, Rosyln said: "Having the right lingerie wardrobe under your look can totally transform your shape. It goes back to the sizing, it elevates the silhouette and you actually feel so much better, everything is in the right place and it enhances your natural shape.

"It's best to work with a personal lingerie stylist to get the best out of your own silhouette and shape.

"You should be 100% comfortable, you shouldn't be conscious that you feel like you're wearing a bra, if it fits you correctly you shouldn't even feel like you're wearing it."

Being fitted correctly is something that Roslyn said customers are becoming more educated about, but that so many women out there still wear incorrectly sized bras. Also, since you can be one size in one brand and a totally different size in another brand, it's always good to "get an expert's advice to avoid badly-fitted lingerie".

Another thing to consider is that even if two people are technically the same size, they will have different shapes, so the types of bras that will suit them will vary wildly. It's always worth trying on a variety of styles to get an idea of what suits your body type and gives you the best silhouette, and a confidence boost to boot.

"Really what we want to do is make our customers have a really relaxed experience, so that they make an informed decision and they're not feeling pressured," said Ros, "They have plenty of time to step back and look to see how the lingerie or shapewear fits them, try it on with a vest over them so they can actually appreciate the shape, or if you have a particular dress for an occasion to bring that in.

"When you have the first experience of wearing the correct size and what that can actually do for you and how good you feel about your body, you never go back, so that's when you essentially become a lingerie addict!"

Here are the lingerie pieces which will see you from day-to-day with ease.

T-shirt bra
Your everyday t-shirt bra should be soft and comfortable, perfectly fitted, and look smooth and invisible under your clothes. If you find one you love it's worth bulk buying it in a few colours, black and nude are staples that you'll always get wear out of.

Strapless bra
Most of us will need a good strapless bra to wear under evening dresses. Many come with detachable, multiway straps which can be used to suit a variety of styles such as from one-shoulder and criss-cross backs. If you have a larger cup size, choose a thicker band to provide more support.

Invisible briefs
VPL is something we all want to avoid, and luckily underwear technology and fabrics mean that seamless, invisible briefs not only do that they say on the tin, but are comfortable to wear too. Find a pair that you feel utterly comfortable in and confident that you can throw them on under any outfit, without hassle.

Good cami top
A good cami top can get you out of many a style dilemma, from sheer blouses and sweaters to underneath suit jackets. Simple silk camis are also getting more popular with the unstoppable 90s resurgence, and look very elegant teamed with jeans and pumps.

Killer piece of swimwear
Shopping around to find the one swimsuit or bikini which makes you feel amazing should be a priority as we come into summer, and there's such a huge selection out there to suit all body types. Once you find something  you're utterly comfortable in, it's sure to be a staple for years to come, so it's worth investing in.

For big occasions, a super-supportive piece of shapewear, be it a control slip, bodysuit or high-waisted briefs can provide the perfect basis for your outfit. Shapewear has come on leaps and bounds, with massive advances in technology which means the pieces are more comfortable to wear, as well as looking attractive. As with lingerie, try to fit on a variety of shapes and styles to find out what works best for you. If you're trying to find shapewear for a particular outfit, it's always best to bring the outfit with you to try on with the pieces.

Top Tip
It's best to hand wash your bras, particularly those with delicate detailing or lace, and never hang the bras to dry by the bra straps as this stretches out the band and will reduce the lifespan of the bra. Instead, hang the bra to dry on the band in the middle of the two cups.