How can I ensure a proper tire bead seal when mounting a new tire onto a rim?

To ensure a proper tire bead seal when mounting a new tire onto a rim, make sure the tire and rim are clean and free of debris. Apply lubricant to the tire bead and rim edge to help the tire slide on smoothly. Use a tire mounting machine or tire irons to carefully seat the tire onto the rim, making sure the bead is evenly seated all around. Inflate the tire to the recommended pressure and check for any leaks.