Mix a little olive oil in water and saturate hair with it, leaving it in for about an hour then wash it out with shampoo. Do this once a week. But you can use other things too like baby oil or mayonaise.
There is a really good brand at beauty supply stores called Aragon oil. The girl recommended it to me. I was skeptical at first, but I love it. It's normal shampoo/conditioner that is sulfate free. It's more expensive than stuff you buy at the store (this is $10.00 each), but it works well. If you are looking for shampoo/conditioner you can get at a drugstore, I like the moisturizing Pantene ProV. That works pretty good too.
Honestly, you do need to start with a good shampoo and conditioner - something from a salon. Store-bought shampoo is very harsh with all of the phosphates. You probably also need a fresh haircut to get rid of split ends. When heat styling, you need some type of thermal protectant like Kenra Hot Spray. If you are high lighting your hair, get the stylist to use color instead of color remover (bleach). You might also want to use some silkening oil (aquage, chi, L'Anza - to name a few). It's applied to clean, wet hair, or dry hair, before styling.
Honestly, it isn't about the name brand of the products but the ingredients in them.
Shampoos that contain sulfates actually strip your hair of its natural oils (which is good for cleaning, bad for moisture) and leaves the cuticles raised, which is also bad for retaining moisture. Your hair likes to stay at a pH of 4.5-5.5 (this is when it is most shiny and the cuticles are closed). Some shampoos have a pH as high as 9 which is highly alkaline and your hair is acidic. The result? Dry, brittle hair bc the cuticles act like shingles on a roof, when they are closed, they keep moisture in the hair, when they are open, moisture goes out as soon as it comes in. So, use a shampoo (preferably sulfate free) that is pH balanced. Aubrey organics has good shampoo (but it is expensive).
Another old fashioned remedy is Apple Cider Vinegar. It helps the pH (but stinks....the smell fades quickly though....and if you follow it with a leave in conditioner, it will disappear immediately). After shampooing, add a good conditioner and leave on while showering and at the end of your shower rinse with water then follow this with a rinse composed of Apple cider vinegar (pH 2-3) mixed with water. Normally 1 part vinegar to 3 parts water. This will leave your hair super soft.
Another thing that I did when my hair was dry was this, take some mayo and olive oil (there are many Youtube vids on this). If you can't take the smell, add your favorite essential oil to the mix. Apply to your hair DRY then put on a plastic cap (plastic bag if you don't have caps) and sit under a hooded dryer for 45 minutes. Your hair will be super soft and ultra moisturized and shiny. But make a change to better hair products. Don't be fooled bc many of those beauty salon brands contain the same bad stuff that the store brands do. Aubrey organics, Alba, and especially Giovanni have good hair products. With Giovanni, use their moisturizing line (Shampoo, Conditioner, and Leave in). Also, add a deep conditioning treatment to your regimen (weekly).
I have very dry hair, especially in the winter, and I swear by Aussie 3-Minute Miracle Deeeeep Conditioner. It's inexpensive and easy to find. My sylist also recommended the Tigi Dumb Blonde line of products for my highlighted hair. It has a protein-rich formula.
I would highly suggest getting a hair mask. I also have very dry hair but I use a hair mas every other week and it has improved exponentially. You get your hair damp/wet and put it on your hair, then cover your hair with a shower cap or plastic and let it sit for 20 minutes, then wash it out. it really helps to replenish dry hair.