1. To determine your ring size, you will require a marker, a ruler, and a string.
2. Take the string and wrap it around your finger, making a mark where it intersects.
3. Use a ruler to measure the length of the string from the mark to the end to obtain the circumference measurement of your finger. 
   OR
4. You can also determine your ring size by measuring the internal diameter of a ring that fits you comfortably.
5. To ensure accurate sizing, it is recommended to have your finger measured by a jeweler.