Makeup artists adjust makeup application for clients with sensitive skin or allergies by taking the following steps:

1. _Consultation_: Before applying makeup, they conduct a thorough consultation to understand the client's skin concerns, allergies, and sensitivities.

2. _Patch test_: They perform a patch test on a small area of the client's skin to check for any adverse reactions to products.

3. _Choose hypoallergenic products_: They select hypoallergenic, fragrance-free, and gentle products labeled as "suitable for sensitive skin" or "allergy-tested."

4. _Avoid harsh ingredients_: They avoid using products containing known irritants like artificial fragrances, dyes, or preservatives.

5. _Use gentle application techniques_: They apply makeup with gentle, light strokes, avoiding tugging or pulling on the skin.

6. _Minimize product layering_: They limit the number of products used and avoid layering too many products, which can exacerbate sensitivity.

7. _Focus on skin preparation_: They prioritize skin preparation, ensuring the skin is clean, moisturized, and primed for makeup.

8. _Use soothing ingredients_: They incorporate soothing ingredients like aloe vera, chamomile, or green tea into the makeup look to calm and comfort the skin.

9. _Be prepared for reactions_: They remain vigilant for any signs of irritation or allergic reactions and are prepared to adjust the makeup application or remove the makeup if needed.

10. _Communication is key_: They maintain open communication with the client throughout the process, ensuring their comfort and satisfaction.

By taking these steps, makeup artists can create a beautiful, safe, and comfortable makeup look for clients with sensitive skin or allergies.