What is the ruling on carrying a small, handmade, body-worn bag on the shoulder or back to place sandals or a small prayer rug in it during circumambulation (Tawaf) and ritual walking (Sa'y) while in a state of Ihram?

There is no harm for a pilgrim in the state of ihram to carry a bag in which he places his belongings. The prohibited sewn garment is that which is tailored to fit a limb. Scholars have explicitly stated the permissibility for a pilgrim in ihram to gird a sword, and likewise to carry a bag.