How to get slick non greasy pin straight untangled hair like mexicans(not being racisicst)?

I have naturally wavy/ straight reddish blonde hair that is always knotty and somewhat frizzy. My Mexican friend has straight hair that is never tangled and even in a convertible stays perfect without knots or frizziness. Is it just in their genes or can I have it too? I use patens medium thick shampoo and conditioner. Thanks