First key ingredient - colour. There is nothing that makes you instantly upbeat like the splash of colour here and there. And if you can make it all about the colour - well, that's even better. One way to do it is to think of some exotic birds with their bold pigmentation.
Of course you can never go wrong with red and with Valentine's day approaching it definately is a go-to color.
And finally - flowers. There is no spring without beautifully delicate subtle blossoms like bluebells or peonies or overpowering allure of exotic flowers. And thus, the flowers are the secret ingredient to every upbeat attire.
If the options presented are too bold you do not feel ready to channel your inner elfin princess just yet you can always start with a hint of color, or change you usual black lace underwear for a fuchsia piece. Also, instead of a flowery dress just pick a head piece. Whichever you choose remember - happy is what we are going for so have some fun with it.