Sometimes shoes that are perfect for that special outfit or a steal at that store price may not exactly be the right size. Wearing shoes that are a bit too big often is more comfortable than wearing shoes that are too small. Fixing a pair of over-sized shoes that have extra space in them is usually as simple as using a filler to stuff the extra space.
Try on the shoes. Walk around in them for a few minutes to see how much extra space there actually is once you begin to move in them.
Stuff the extra space in the toe with a soft filler. Cotton balls or tissue paper work great as a filler because they provide softness and will give a bit when you walk. Use enough of either to fill the extra space in the shoes, but not so much that the filler is packed around your toes. You want to keep enough space for movement; shoes that are the right size still have adequate space in the toe for movement.
Try both shoes on again. Walk around with the toes stuffed for a few minutes. Make sure your movement is still comfortable after the filler has settled. Add or remove filler as needed to make the shoes comfortable. Repeat this process until the desired level of comfort is achieved.
If the shoes still feel too big after stuffing the toe, try adding an insole as well to achieve a more centered feel.