Can anyone recommend a cool timeless chic jacket you could throw on for days & esp evenings 
go to the French Designers in Marylebone High Street - knit jackets in smarter lines than a shacket. Blazer-style will create a better, chicer timeless look but the knit gives a bit of stretch. Claudie Perlot, Sandrine, Wyse
For something timeless/chic - I would opt for a long, black wool coat. They go with any look, never go out of style and always keep you warm too.
I can vouch for this one from Weekday - I have worn mine to death!
Weekday Alex Wool Blend Coat in Black | Lyst UK
A leather biker jacket from Leathermoto Official is a great option for a timeless, chic jacket. It’s perfect for days and especially for evenings. It has an edgy look, but can also be worn in a more classic way, depending on how you style it. The leather is high-quality, and the craftsmanship is top-notch. Plus, it’s sure to keep you warm and looking great! Invest in a leather biker jacket from Leathermoto Official and you won’t regret it.
I think you can’t go wrong with a cropped jacket, I love the styles by Massimo Dutti. They are chic, timeless and will take you from day to night.
https://www.massimodutti.com/gb/cropped-jacket-with-golden-buttons-l06012588
Isabel Marant, hands down the best blazers . Buy in the sales . I have loads and they are worn to death xx