One of the biggest haircare mistakes (even if you didn't recently deliver and are experiencing unprecedented hair fall) is brushing wet hair.
Over-brushing, in general, can cause breakage; but brushing hair that is wet, now that's one of the worst damage-inducing things you can do to your strands.
Hair is weakest when it’s wet, and wet hair is more prone to tangling. Postpartum shower scaries can already result from seeing hair fall; but to minimize breakage on top of that and to prevent shower-induced snarls, give your hair a brush before hopping in.
Now if you are adamant and like to brush in the shower or feel it's the only way to detangle, then lather on the deep conditioner prior to combing or untangling your strands with your fingers, and always use a wide-toothed comb rather than a brush (fingers are still best in this case) before rinsing.
The exception: Curly hair
If you have curls you know they break easy and can be prone to dryness so you must treat them with care. Combing your hair when not damp or wet will lead to breakage and split ends.
Your best option for keeping your curls shape and maintaining healthy ends is to use a wide-tooth comb when in the shower while you condition.
Once out of the shower continue to minimize breakage by avoiding intense towel drying. If your norm is to rub your hair with a towel to speed up the drying process; STOP. Rubbing hair too intensely will create a rough hair cuticle.
The cuticle is the outermost layer. Made of flattened cells that overlap like the tiles on a terra-cotta roof, the cuticle protects the inside of the hair shaft from damage.
Instead, gently blot hair with a towel. Your hair will be healthier with less breakage-inducing friction.