Some well-intentioned habits can actually strain the barrier. A common mistake is over-cleansing: washing many times daily or with harsh products removes natural lipids and NMF, leading to dryness.
The second is using too many products at once. Layering multiple actives can tire the barrier, especially in sensitivity-prone skin. The third is starting all new products simultaneously — making it impossible to identify the cause of any reaction.
Other frequent mistakes: over-exfoliating, washing with very hot water, skipping sun protection, and switching products without giving them time. Since the renewal cycle is about 4 weeks, wait that long before judging. The key to sustainable care is "less but right".