Shampoo is not "just a shampoo", it is instead a fundamental phase to prepare your hair to receive the later treatments. When your hair is over washed or not properly conditioned, it could result electrostatic and dehydrated. A small amount of oil or conditioner will make your hair moisturized and brushable.
2 - TOWEL DRY YOUR HAIR GENTLY
Rubbing your hair too aggressively will make it frizzy and damage the cuticles. Always remember that the wet hair phase is the most delicate one.
3 - DISTRIBUTE EVERY PRODUCT EVENLY
To make sure you distribute the product all over your mane, try to apply it on the brush and then comb your hair by involving roots, lengths and ends: you'll get the right support for your blow dry without weighting your hair down. Volume in the root area is fundamental to give your hairstyle a beautiful shape, so better to apply more product in the root area and fade it towards the ends, like this the hair will result lighter.
4 - FINGER DRY YOUR HAIR BEFORE BLOW DRYING
By removing as much water as possible before blow drying, you'll reduce the drying time and you'll make the blow dry brushing less traumatic for your hair.
5 - START THE BLOW DRY FROM THE ROOTS AREA, NOT THE ENDS
This is crucial to create the greatly desired volume but it couldn't be enough if your hair is long and you have a one length haircut, that's why it is essential to have a layered base hair cut look.
6 - TRY ANTI-HUMIDITY PRODUCTS
Especially in wet climates hair could get filled with humidity, by doubling its weight and going flat. An anti-humidity product is what you need to get a long lasting volume.