I didn't start from scratch, but I did have to really change my wardrobe after I had DC, got made redundant and moved house all in the space of a year!
I had to get rid of nearly all my work clothes, as I wasn't using them. I now have a wardrobe I'm reasonably happy with. It is small, but that actually suits my lifestyle at the minute. I don't go 'out out' all that much and very rarely anywhere which needs me to dress up. I mainly dress for school run, maybe the pub, running and walking these days.
I can tell you what's in my wardrobe if it helps, but probably won't be super relevant if you have a different lifestyle!
Blue jeans
Grey jeans
Navy harems
Shorts for summer
Casual skirt
Long sleeve tops (all blue and navy)
Short sleeve tshirts (all white and blue)
3 x knitwear layers (all blue and navy)
One dress for events or going out somewhere nice-ish, but which can get dressed down as well
An old skirt suit for interviews in case I ever need it!
Shoes:
Lace up black boots
Sturdy sandals for summer
All birds ballet flats
Running shoes
Hiking boots (these have just died and I'm thinking of replacing with cross trainers for hiking and running, so I can get rid of the running shoes too, as they are also on their last legs. One pair instead of two will save some space)
I think, for me, the important things are having a small colour palette, so things go together. Mine is blue, navy and white. Decent fabric, preferably natural fibres and comfortable (nothing too tight or heels I can't walk in for example). Also having hardworking items in my wardrobe. Preferably machine washable as well.
I think about this quite a lot sorry! Bit of an essay 
Also, my clothes aren't particularly expensive. I try to buy secondhand or from sustainable brands and I think buying one item which serves more than one purpose means I inevitably buy less. So, no specific items, like super fancy dresses which I could wear to a wedding couldn't wear out for dinner or to the office, (if I had one), or loads of different colours which don't go with each other. If you buy one versatile, nice piece and wear it all the time, it works out cheaper.