You always have a bag packed so you'll be ready to go at a moment's notice. It has to be utilitarian, but there's nothing that says it has to be ugly!
Find a functional as well as fashionable piece, big enough to carry all your essentials, that doesn't look like an army rucksack.
Pick a classic roomy shoulder tote or a structured sack for your personal electronics, beauty essentials, and change of clothes (in drip-dry, packable fabrics that won't make you look like a Shar-Pei at your destination!), pockets for travel docs, and shoulder strap for hands-free carrying.