Eat lots of food rich in omega 3 oils like salmon, sardines, avocados, olive oil. You can also take fish oil, biotin, zinc, vitamin b3...I usually take this on a daily basis.

Doing a protein mask for your hair is beneficial as well. You can incorporate olive oil and coconut oil with a whole egg, comb it into your hair, cover your hair in a plastic wrap for a few hours and then wash it out.