When using rollers for a bouncy blow dry, it's important to section your hair properly to ensure even heat distribution and a smooth, voluminous finish. Here's how to section your hair for rollers:

1. Start with clean, damp hair. Use a heat protectant spray to protect your hair from the heat of the rollers.

2. Use a wide-tooth comb to detangle your hair and remove any knots.

3. Divide your hair into four sections: the top, sides, and back. Use clips or hair ties to keep the sections separate.

4. Starting with the bottom section, take small sections of hair (about 1-2 inches wide) and roll them onto the roller, starting at the roots and rolling down to the ends.

5. Roll the hair section tightly around the roller, making sure that the hair is secure and smooth. Repeat this process for each section of hair.

6. Once all of your hair is rolled, use a hairdryer to dry the rollers. Make sure to keep the hairdryer moving and use a low heat setting to avoid overheating one section of hair.

7. After the rollers are dry, take them out one by one and gently unroll the hair. Use your fingers to shape the curls and add volume.

8. Finish off with a light hold hair spray to set the curls in place.

Remember to work in sections, this will make it easier to handle your hair and ensure that all of the rollers heat up evenly. and use the right size roller for the size of the curl you desire.