I get a lot of emails usually from women who can't figure out why their hair is breaking. In most cases it relates to an imbalance of protein and moisture within the hair can be quite tricky to address. However there are also other common ways hair breakage occurs and it's usually simple tweaks that can limit the damage.
1 Rough Styling
Plain and simple, if you detangle too roughly or force your hair into tight styles it's going to break. Breakage tends happen along the nape and crown as the hair here is more delicate. Vary the positions of your ponytails and buns as wearing it in the same place day in day out creates tension which weakens the hair. Be careful to detangle from ends to roots to prevent snagging or snapping the hair too. Wide tooth combs or your fingers will do the least amount of damage so I rely on these more than brushes. Also be careful not to manipulate your hair too much when it's wet - as this is when it's most fragile. I tend to leave my hair alone completely until it's about 80% dry.
2 Hair tools
Certain clips, combs and hair bands can break the hair. It's usually styling accessories which are made with metal - bobby pins, clips, headbands - as these all have sharp edges which can catch on the hair. It's up to you if you continue to use these (I personally still use bobby pins) but be careful to put them into the hair gently. If you want gentler alternatives, look for products made of soft fabrics like hair bands made of silk or satin or you could just put a bit of oil or leave-in conditioner over your usual accessories.
3 Chemical processing
Overprocessing the hair with relaxers, hair dyes or perms will weaken the hair making it more likely to break. It's hard to reverse damage from overprocessing but increasing deep conditioning sessions will help. To avoid breakage reduce the amount of chemicals you put on your hair and how often you use them. For example, if you relax your hair every 6 weeks, try to wait until 8 weeks instead.
4 Heat abuse
You love the perfect blowout, smoothed out style or bouncy curls delivered from a barrel tong but too much heat styling wreaks havoc with those tresses. It depletes both protein and moisture levels and often we don't replenish these with enough deep conditioning sessions. If you must use heat regularly also do the necessary conditioning and moisturising to keep your hair in tip top shape. Limit your heat usage to once per week or less and you'll notice less breakage.
5 Thinning ends
Thin ends are often very fragile so break easier than the rest of your hair. Unfortunately once your ends are thin you're kind of limited with how much thickness you can regain. This means that often you have to cut out the thinness. I know first hand that it can be hard to let go of thinning ends, but once you cut them off you'll notice an instant improvement in breakage.
Of course there are other ways that breakage can occur but these are the main ways I've noticed
How do you prevent breakage?