Wearing a blazer with jeans is a great way look elegant but, at the same time, casual. A blazer and suit combination done right is a very versatile outfit, which you can take from day to evening and which you can easily dress up or down.
Make a deep blue trenchcoat and tan chinos your outfit choice for drinks after work. For shoes, rock a pair of dark brown leather casual boots. Loving how this look brings you into fall mode in seconds time.