Looking more like a snooker player’s waistcoat, this natty hounds-tooth/diamond-pattern sleeveless cardigan (£25) from Topman might be a little bit "granddad" for some, but I love it. The cardy would look great with a long sleeve, crew neck tee underneath or a light coloured shirt with a loose, skinny tie. Pair up a pair of dark-brown slacks and top off with a trilby or flatcap.
If you need another layer in these cold, damp days (it’s summer for God’s sake) then you could go a bit Arthur Daley and add this wool trenchcoat (£80, also Topman). It could be so good for you!