We would recommend the following steps to effectively use a shampoo bar:

1. Wet your hair thoroughly with warm water.
2. Wet the shampoo bar and rub it between your hands to create a lather.
3. Apply the lather directly onto your scalp, starting at the roots and working your way down to the tips of your hair.
4. Massage the lather into your scalp for a few minutes, using your fingertips to stimulate circulation and help remove any dirt, oil or build-up.
5. Rinse your hair thoroughly with warm water, making sure to remove all the shampoo from your hair.
6. If necessary, repeat steps 2-5 for a deeper cleanse.
7. After rinsing, you can condition your hair as usual, or simply comb through with a wide-toothed comb to detangle your hair.
8. Rinse your hair thoroughly with cool water to help seal the hair cuticle and give your hair a shiny finish.
9. Gently towel dry your hair or let it air dry.

It is important to note that shampoo bars are typically more concentrated than liquid shampoos, so you may not need to use as much product. Also, it is important to store your shampoo bar in a dry, cool place between uses to extend its lifespan.