A bag is usually the last thing chosen and the first thing noticed. Three small decisions make it look intentional.
Proportion
Balance volume with volume. Oversized coats and wide trousers suit a larger tote or a slouchy shoulder bag; tailored, close-cut pieces pair best with structured top-handles and compact crossbodies.
Colour
Either echo one tone already in your outfit — a cognac bag with camel, burgundy with plum — or let the bag be the only colour against black, ivory or grey.
Strap length
A crossbody sitting at the hip lengthens the line of the body. Worn higher, at the waist, it reads sharper and more modern. Shoulder bags look best tucked just under the arm, not hanging mid-back.
Start with one rule, not all three. The best styling still looks like it took no effort.