A little step by step...
1. firstly, and most importantly is your diet. Expensive shampoos or fancy salon treatments are not key to get a healthy, strong and shiny hair. Of course a good shampoo and treatments does a lot, but it is only fixing the "problem" from the outside. Just as shaving will not stop your hair form growing. Eating a variety of healthy foods will give your hair a boots and the rest of your body will thank you.
What you need to eat to get and remain shiny, strong and healthy hair (as well as rest of your body) is protein, iron, vitamin C, omega-2, vitamin A, zinc & selenium, vitamin E and biotin.
What I can recommend is eating spinach. Spinach contains vitamin A, vitamin C, calcium, iron, vitamin D, vitamin B6, vitamin B and magnesium. I have recent been putting spinach in my smoothies and added bananas; the only thing you will taste is the bananas - therefor it works wonderful if one isn't a big fan of spinach (even though spinach does not have a strong flavor). Also cooking it with eggs is a good idea.
2. Find a shampoo that does not irritate your scalp. In my case, Paul Mitchell Extra-Body Daily Shampoo. And an balsam/conditioner that gives your hair hydration and makes if feel nice (I have so far been using: Paul Mitchell Extra-Body Daily Rinse)
3. After showering, try to not blow-dry it, instead use a towel - gently squeeze your hair dry with the towel. Your hair will most likely still be a little wet: this is the best time to add some leave-in conditioner or another product, since the hair will absorb the product much better. Personally, I like to use some kind of oil (morocco oil or argan oil). some people might think my hair would feel oily. However, since I do this while my hair is wet - my hair absorbs the oil and when the hair is dry it will feel soft, shiny and healthy (not oily).