The best advice is to hydrate your body the first enemy of your skin and hair is dehydration so always take 2-3 liter of water per day till the color of your urine turns to white.
As much as you can delay the starting of dying your hair as it makes hair weak in a long-term, also use very light makeup and start again later as much as you can we see now lots of 10 years old that doing makeup so it can harm the skin.
Taking food and supplements like iron, zinc ,selenium ,vitamin C and E ,A ,collagen ,turmeric, papaya, salmon, sweet potato, carrot,eggs,avocado,spinach,green tea,blueberries,kale,brazil nuts,oat,walnuts,almond,whole grain meal, and bread,oyster,dark chocolate, red and yellow bell peppers,soy,broccoli, sunflower seeds ,coconuts oil ,or fresh coconuts, olive or olive oil,tomato,fatty fish.
Do not chew your nail or pull your hair whenever you are anxious. Take care of your blood pressure, cholesterol, and especially sugar level as they have the tremendous effect on skin aging procedure.
In dry weather try to hydrate deeply your skin also protection from sun is so important for the best protection from the sun you need to use sunscreen cream 30 minutes before exposure and SPF 50+ is enough also every 3 hours you need to repeat it if skin is so sensitive to the sun you can use zinc oxide as mechanical barrier along with sunscreen cream as well .
Check your vitamin d level and correct it if you have the deficiency. You can soak your nail for 20 minutes on cup of raw egg whites
Stress can have the direct effect on hair and skin, relaxation can have a dramatic effect on hair and skin, taking shower before sleep, spa, massage, yoga all can help for having better skin, nail, and hair.
Anemia also is important so always better to check for hemoglobin and iron level in your regular checkup especially in the female.