" dragonprincess:The main problem with my hair is that it is too thin and I can only grow it to a bit more than shoulder length before it becomes really messy with spilt ends. Is there a way to avoid split ends? "
A few words as the forum's resident hairdresser! I don't know what your hair is like really, but I wrote down some general guides.
Hair has a certain pre-decided length based on your genetics. Sometimes, it can grow longer as you are growing, but once you stop at the end of your teens, you usually get your real lenght.
Hair grows in three phases.
First, it grows out, and the length it gets/the period your hair grows varies a lot among people.
Your hair gets longer by on average 1cm in 4 weeks, and about 10-12 cm per year. So for someone who can grow hair to just past the shoulders but not longer, that's because the growth period is about 4 years. The hair on your head isn't all in the same cycle of course, some of it grows, while some of it is in the next phase, which is the "just being there, but not growing anymore."
I don't remember exactly how long that phase is, but a while. Then the third phase is where the strand starts to loosen from the root and eventually falls out.
Hair is greatly affected by your general health and diet, try make sure to eat healthy fats and vitamin-rich food. Especially vitamin B is often talked about. If you are sick or stressed in periods that often shows on the hair. It gets dryer. Strands may end up in the "falling out" phase sooner than they should.
The hair grows better if there's good blood circulation in the scalp. Smoking can make this worse as it constricts blood vessels. (And also "eats up" vitamins.) Gently massaging your scalp while shampooing is a good idea. Also product buildup or if you have some dermal flaky issues like psoriasis, can cover the roots and hinder the hair from growing.
When it comes to split ends, people with fine strands have a harder time because the hair is less robust. It's important to trim the ends regularly, especially if you get spilt ends fast, as the split travels upwards on the strand if it's not cut of cleanly.
Hair gets broken by many outside factors like hairbands with metal pieces (metal gnaws off the strands) or just a cloth hairband that's always in the same place, or tied very tight. It can break off against clothes, your pillow, ungentle brushing... I would recommend plastic hairclips. Sleep with your hair in a braid. Use a tangle teeser type brush. Always be gentle and start detangling from the ends.
To make the hair look fuller and healthier, don't get it layered, keep the ends blunt. If you want something to happen in the hair and not just have everything the same lenght, get the front pieces layered/sliced downwards. Or if you get it layered, there should be a lot of weight left at the formline, and the layering should just be very soft and blended at the upper layers of the hair.
And don't do chemical treatments, bleach being the worst offender. If you color your hair, never apply color on already colored parts (lenghts). Use a pigmented mask instead.
Use a shampoo and conditioner based on whether you need moisture or not, if you have an oily or dry scalp etc. It might be worth finding a shampoo with gentler surfactants, sodium laureth sulfate and sodium lauryl sulfate are harsher surfactants. Find a balance with a gentle shampoo, but which doesn't weigh your hair down. There are volume shampoos like eg Lanza Volume which creates like a coating on the strands that makes them fuller. And "protein" shampoos which also build up the strands. Basically what they do, and which you also can find styling products that do, is that they contain polymers which strengthen the strands from breaking. This can actually be good, as long as it is a product which solves with water and a gentle shampoo, and not a product with just builds up and builds up (which is not so good).
Some people find that Olaplex treatment works (it's a product you can buy and use a t home like a treatment). Olaplex is a bit special, as it is a patented product which is supposed to reconnect broken bindings in the hair cortex. (On a chemical level. Hair is held together by several different types of bonds. For example hydrogen, salt, sulfit and another one which I can't remember the name of right now. When you do a perm for example, the sulfit bonds are temporarily broken and refixed. So those can be tampered with, and Olaplex allegedly can mend those broken by wear and tear. If the bonds with the forgotten name are broken however, your hair dissolves. They might be called peptide bindings...)
To be honest I can't really stand behind recommending Olaplex, because I have varied experience with it. I think you might be just as well off with normal mask with oils and moisture. Or try coconut oil, or other vegetable oils. Some people however swear by it. Then again some people experience the hair becoming stiff and breaking off. We are not sure why but suspect ingredient in other products/shampoos interacting in a bad way. It's also hard to get a straight answer from the representatives of the brand, which to me is not a good thing...
Anyway, be gentle when you have washed your hair and it's still wet, don't rub it with a towel just press out the water/wrap it in a turban. Use some kind of leave in product, like something moisturizing and detangling. I can recommend products if you like, but in general something like the Revlon Uniq1 or some other creamy product will probably work. People also have different opinions on silicones or no silicones... I can get into that if you want, but yeah that's also a complex discussion. And of course, try to minimize hot tools. Blowdryers can be alright if you are gentle. Washing 2-3 times a week is good. More often is not so good. Dry shampoo can be nice in between washes, also some dry shampoos are good at getting volume at the roots, if you want that kind of styling.
Lastly, hair extensions are a thing of course. But it is pricey. And is a bit of a kerfuffle. I would in that case recomment tape, as keratin bonds are not nice to the hair.
Hope you got something useful out of this!