My hair is pretty awful, it's course, frizzy and very dry. To make matters worse, I colour it, blow dry it and straighten it, so left to it's own devices, it resembles brittle straw.
After a lot of experimenting I've finally found 2 shampoos that work amazingly well for me. The first is Redken Extreme Shampoo which contains protein to help strengthen weakened hair, I felt a major improvement after using it for just a few weeks, my hair was breaking less and felt more resilient.
The second is Kerastase Nutritive Bain Oleo-Relax Smoothing Shampoo, which is formulated for dry, course and rebellious hair. This is hands down, the best shampoo I've ever tried, I've been using it for a really long time and have repurchased it more times than I can count! I leaves hair feeling clean but also really soft and nourished, which makes styling a lot easier. I don't know how it works, it just does!
With both of these shampoos, a little goes a long way as they foam up really well, so a bottle lasts a lot longer than most, making them worth the higher price tag. I tend to alternate them, which I find works the best for me, my hairdresser informed me that you shouldn't use protein products too much because your hair needs moisture as well as strength.