How can I make it so I get thick hair?

No easy way to do it. A person who thinks she is losing hair or has hair strands that seem thinner than in the past, she can see a primary care doctor to rule out medical conditions such as thyroid disease or other autoimmune disorders. If all is normal, but the hairs are thin or finer, then the patient can research the internet to see which shampoos, conditioners, and hairstyles might make her hair look thicker.