Many people don't really know what their doing when they buy hair from what I've observed. I'd like to give some suggestions and then follow up with some advice on caring for the hair.
First, make sure you have researched the type of hair you want to purchase. Synthetic? Cheap, but looks like doll hair. It's made from synthetic fibers, and isn't heat resistant *unless specified* Synthetic hair holds its shape well, but there aren't many options, and don't expect to get months of wear from them, even with the best of care you will eventually have a tumbleweed. It will matt, tangle and frizz up no matter how expensive the products you use are. This leads me to the next point. Do not waste money on expensive products if you have synthetic hair! There was a lady bragging about how much she spent on her "synthetic wefts." Sometimes you just have to let people feel they are all knowing. I've been there so, I didn't fault her. Too bad that Pureology had no chance of doing anything to that synthetic fiber. She would have been better if she had washed her "purse dog" with that
Now, when you get to the human hair, you become a small fish in a huge pond. There are so many types of hair but the most common are: Indian Remi, Yaki, Virgin and Virgin Cuticle. Depending on your own hair's texture it will determine what's most natural in terms of blending. The good thing about human hair, is that you can customize it. It can be permed, colored, relaxed, and flat ironed. The best hair, in my opinion, is virgin cuticle. This is hair that has not been treated at all. You know when you donate hair and they don't want processed hair. That's an example of virgin hair. The cuticle intact helps to prevent frizz. The unattached hair is good, but because it isn't aligned (same direction) it's more susceptible to tangling, which means shedding.
How you care for your extensions should mirror how you take care of
(you too can have this hair)