Whats the best shampooing tips and conditioning treatment for dry hair?

Less of 1, more of 2. Most dry hair is caused by over-shampooing and over-blow drying, no matter what you've read. Shampoo less frequently, perhaps only once or twice a week; add a conditioner (any good one will do); avoid blow drying and harsh styling products. That will work 99% of the time. If it doesn't, see your doctor to rule out an underlying cause.
Dry hair. Get enough sleep,avoid excess sugar & fat, v carbonated drinks, eat enough protein, exercise regularly. Insure you have adequate Iron (like kale & other dark green leafies), Omega 3 fatty acids (like walnuts),vit.E (fruits & veggies), D & B vitamins, biotin & zinc. Avoid sulfates & formaldehyde in shampoos, over-washing, excessive blow dry heat & curling irons. When needed use quality conditioner.