At the very least, you should be prepping your strands with a heat protectant before blow-drying. One of the biggest culprits of hair damage is a lack of heat protection.If you have thick hair, work styling products into sections. If you have thin hair, apply products halfway down through the ends to avoid greasy-looking strands.The reason for working from root to tip when blow drying is because this is the direction of your hair growth. Working against it opens the cuticles of the hair shaft, encouraging tangles and frizz. Always blow dry from root to end to fuse the cuticles, and add shine to your hair strands.