Most people develop hair care habits early and rarely revisit them. The problem is that many of those habits, from how often they shampoo to how they dry their hair after a shower, are doing more harm than they realize. Board-certified dermatologists have a clear point of view on what works, and a lot of it comes down to understanding your own hair before reaching for any product.

Start with knowing your hair type

Hair type is the foundation of any effective care routine. Whether your hair is straight, wavy, curly, coarse, fine, or tightly coiled, the products and practices that will benefit you are different. Many hair care lines now label their products using a numbering system that runs from fine and straight at one end to thick and tightly coiled at the other. Choosing products that match your actual hair type is the starting point, and skipping that step is where most routines go wrong from the beginning.

How often you wash matters more than you think

There is no universal answer to how frequently hair should be washed. Dermatologists generally advise people with straight hair and an oily scalp to shampoo daily if needed. For dry, textured, curly, or thick hair, washing every two to three weeks is often sufficient. Washing too frequently strips natural oils from hair types that need them most, while washing too infrequently can lead to product buildup and flakes. Those flakes are often mistaken for dandruff when they are simply a sign of washing too seldom or using the wrong moisturizer or conditioner for the hair type involved.

When shampooing, the product belongs on the scalp, not distributed across the full length of the hair. Applying shampoo at the roots allows it to clean away buildup, dead skin, and excess oil without drying out the ends of the hair, which are the oldest and most fragile part of each strand.

Conditioning and the healthy hair routine

Conditioner is not optional. It restores moisture, reduces tangles, and makes hair easier to manage after washing. How it gets applied, though, depends on hair type. For fine or straight hair, conditioner should go on the ends only, since applying it near the roots can leave the hair looking flat and weighed down. For dry or curly hair, running conditioner through the entire length of the hair is the more effective approach, since those hair types need more consistent moisture from root to tip.

Detangling is another area where technique matters. Wet hair is structurally weaker than dry hair, which means it breaks more easily under pressure. A wide-tooth comb is preferable to a brush on wet hair. For thick or curly hair, dermatologists suggest combing in the shower before rinsing out the conditioner, since the slip from the product reduces breakage. For straight hair, it is better to let it partially air dry before combing, and to start from the ends and work upward rather than pulling through from the root. Drying hair by pressing a towel or a soft t-shirt against it is less damaging than rubbing vigorously, which disrupts the hair’s outer cuticle and creates frizz.

What heat actually does to hair

Heat styling affects all hair types, not just the ones commonly described as fragile or delicate. Blow dryers, flat irons, and curling irons all cause damage when used at high temperatures or without a heat protectant product applied first. Dermatologists consistently recommend limiting how often heat tools are used, choosing low or medium settings when they are in use, and applying a heat protectant before styling. The goal is not to eliminate heat styling entirely for most people, but to stop treating it as consequence-free.

For persistent scalp conditions, unexplained hair loss, or hair that does not respond to changes in routine, a board-certified dermatologist is the appropriate next step. A lot of what passes for bad hair days is actually addressable with the right clinical guidance.