For my recent visit to the House Of Lords I wore a sleeveless bodycon dress by Marks and Spencer which is very comfortable to wear and doesn’t crease much. The red jacket added a nice splash of colour and as it is a slim-fitting jacket really brings in the waist. I only had a small overnight case so not much room for clothes for the next day (I travelled from Bournemouth to London on Friday and stayed overnight in London, stopping for a late lunch with a friend on Saturday before heading home).
My solution to the lack of baggage space was to retain the red jacket and replace the dress (which took up very little room in my overnight case) with a blue top and skinny jeans. I actually wore my trainers as there are too many escalators and stairs between London and Bournemouth on the train and tube journeys!