Pieces Every Wardrobe Needs: Part 1, Top Half

Plain/Minimalist T-shirt - Pair with a blazer and accessories to dress it up, or jeans and converse for the all american look. 

Colours: Black, White. Add a primary colour like red for a more diverse wardrobe choice.

Slogan/ Picture/Patterned Teeshirt: Not an essential, but i thought id throw it in here as everyone needs a bit of fun fashion in their wardrobe. Slogan and picture tees are really easy to get hold of and there is so much choice. Henry Holland do fun ones. grey by-henry-holland
Colours: Any. Just make sure its not too childish or too offensive like this outfit choice at Coachella. Coachella: Eat,sleep,rape,repeat

Plain/Minimalist Cotton Shirt: Long sleeved or 3/4, a buttoned up shirt goes well for work, or open over a coloured or slogan teeshirt with denim shorts, looks effortless in spring.
Colours: White.

Cardigan: Rain or shine, you will always need a cardigan. A thin one can be put under a jacket if you need some extra warmth, whereas a thick chunky knit or cable knit is a real staple in Autumn. Colours: Any.

Blazer: Whether its a casual or smart event, a blazer can pull together any outfit. Whilst a black blazer goes well with just about anything, a coloured blazer adds a bit more spice to an outfit. For example, a bright coloured blazer over a black or white dress can look amazing.
Colours: Black, Navy, White, Red, Tan etc..

Leather Jacket: Channel your inner rock god or goddess and invest in a good quality leather jacket. A leather jacket can take you from autumn to spring and back again. Opting for the shiny reflective kind can end up looking tacky and cheap, so it's worth investing your money in a 'matte' one. A black leather jacket over a pretty dress can toughen up the look, Pairing with light denim jeans and a pretty teeshirt can also look nice.
Colours: Black or Brown, although other colours, if done right, can look amazing too.

Teeshirt Dress: A real versatile piece, a teeshirt dress can be paired with leggings and a cardigan for winter, or with some sandals and a hat for summer. Colours: A plain one is a good idea and you can dress it up or down with accessories, but also patterned ones are ideal for summer.

Smart Cocktail/Evening Dress: Something incase a special occasion arises. Makes sure it fits perfectly and also make sure it can cater to more than one event. Ie, don't go getting a candy floss ball gown at £3000 if you're only going to wear it once. Get a nice one that can be worn for a party but also possibly for a formal occasion.