In a recent post (The modern man needs a good blazer) you explained how versatile a blazer or odd jacket can be, and how to wear one. The image, however, showed a jacket with a shirt and tie, and jeans. Do you think this works well? Or is a tie too formal with jeans? I like the look but don’t know whether I could ‘pull it off’ as they say.
It absolutely can work, but it is one of the hardest things for a man to get his head around because there are so many moving pieces. The contrast with a navy suit and black shoes is pretty stark.
The keys are colour and texture. More subdued colours and rougher textures are more casual. Match these to the casualness of the jacket, trousers and shoes.
As jeans are pretty much the most casual trousers you can wear with a shirt and tie, both should be as casual as possible. A blue shirt is more casual than a white shirt. A wool tie is more casual than a silk tie. A knitted tie is more casual than a printed tie. An oxford-weave shirt is usually more casual than a smooth twill.
That extends to design elements as well. Single cuffs are more casual than double cuffs; plackets are more casual than plain fronts; button-downs are more casual than spread collars.
Hopefully you get the idea by now.
The image from Brunello Cucinelli that you refer to (reproduced below) includes a white shirt with a spread collar and single cuffs, and a woven, cashmere grey tie. Personally I would have gone with a button-down shirt rather than a spread collar, or a blue shirt, but you can see how casual elements have been included to make the shirt/tie fit better with the jeans and brown jacket.
The image at top, taken from The Armoury’s wonderful Tumblr account, also uses a white shirt but you can see how the knitted silk tie adds a casual element. Suede in the belt helps too – more texture.
Good luck with your combinations.