1. Combs should be designed to be sturdy, heat-resistant, soft, and elastic, with no sharp edges.

2. Hair brushes should be easy to comb and curl hair without damaging the hair quality.

3. Combs with rounded teeth are better than those with pointed teeth, as they are less likely to damage hair.

4. Brushing your hair does not need to be too dense, so as not to damage the hair.