I'd start with great jeans - for me that would be a straight leg black Jean (I love the Jigsaw ones) as they can be worn anywhere dressed up or down. A couple of silk shirts or t shirts. A trench coat for Spring. Some scarves.
I'd do a virtual shop first ! Create a board on Pinterest and get some style tips and recreate from there ! Sometimes you can alter /add to existing items too ?! Then when you know that will suit you / your budget / etc go for it !!
It all depends what you need clothes for - are you a SAHM or do you go out to work, if you work what kind of place you work in etc.
I work FT in a not too smart office. My wardrobe basics are:
1 pair of jeans (ICHI) 1 denim skirt (Boden) 2 pairs of navy leggings (Monsoon) 1 denim tunic dress (Boden) 1 navy and white stripy long sleeved tunic (Seasalt) 1 light blue and cream stripy long sleeved tunic (Seasalt) 5 Breton tops - two navy with white stripes, two white with navy stripes, one light and dark grey (Boden) 2 pairs of wide leg trousers - 1 navy, 1 black (East) 2 fitted shirts (Charles Tyrwhitt) 2 cashmere mix jumpers (Boden) - these are quite warm 2 fine knit cotton jumpers (Great Plains) - these aren't as warm 2 intarsia jumpers (Sugarhill) 1 plain navy jersey dress (Boden) 1 print jersey dress (Boden)
But my wardrobe is based around what I need and what suits me. Which seems to be mainly navy and stripes
I also have a lot of scarves. And a coat. And some shoes.