Here's what I'm packing for 3 days away in London with work in the office and on training so outfits are more business casual than smart suits.
I thought it might be useful for others to see what I've packed.
1 plain black cardigan
1 pair dark charcoal grey trousers
1 pair medium marl grey trousers
1 white shirt
1 pink shirt
1 striped shirt
1 grey knit top
black bag, black shoes, black leather gloves and black zipped raincoat with a bright scarf.
Pjs, underwear, socks, toiletries
The cardigan and jacket can be layered if cold, or worn alone with any of the tops and all the items mix and match with each other.
The shoes can be worn with all the outfits and are comfortable for walking around London.
I like to have a second bottom, and a spare of top, socks and underwear.
Now if you wanted to expand this wardrobe further you could add a couple more toning tops, a medium marl grey jacket, plain black trousers perhaps even a bright pink cashmere sweater (I have all these things but am not taking them). With some different shoes you could add a skirt and dress as well and lots more combinations become available to you.