A healthy diet that includes proteins, leafy greens and omega-3 rich foods like salmon will help. Staying hydrated with water. Stress can also affect hair so try exercise, yoga or meditate. Some medications can also cause hair trouble.
Genetics will also play a part in what type of hair you have. Go easy on products you use on your hair like dyes, shampoo's, hot irons and rollers. Do not brush vigorously, be gentle.