How to prevent damage and hair loss.
First thing you have to remember, anything that you do to your hair, other than leaving it alone, could be damaging. It depends on the type of hair you have. Some people have strong hair; some people have weak hair. So just pulling it back in a ponytail could damage some people. So the best thing to do is to try to determine the strength of your hair.
Don't wear your hair too tight. Don't braid it too tight. Don't let anyone weave it too tight. If it's tight, let them know. Tell them, "It's too tight. Take it out. Do it again." If you see your hair pulling at the hairline, if it's painful, if you see blood, some people have done that, take it out immediately.
Also, wetting your braids just makes them tighter. Some people think that they can wet them to loosen them up, but it actually makes them tighter, so you can cause yourself more pain and more damage.
So the best way to not have any damage to your hair is to not braid it too tightly, not weave it too tightly. Don't put it in a ponytail too tightly. Try not to flatiron it too much. Try not to actually over-relax it. Never color and relax your hair. You cannot do a keratin treatment over a relaxer; remember that.
This way, if you keep these things in mind, you will minimize the damage or hair loss to yourself.