Thinning Ends

You can identify whether or not the ends of your hair are thinning by taking about 2-3 inch section of your hair.. combing it straight out ,holding your hair out at a 90% angle using your index and middle finger run down the shaft of your hair. If you notice transparency at the ends.. Those are your thinning ends.

Normal Thinning:
Very Long Hair
For one, a slight thinning of the hair’s ends occurs during the normal, healthy progression of hair growth. Hair thins out towards the tips due to the gradual “weathering” that a head of hair faces throughout its lifetime. The hair nearest the ends is the oldest hair on the head, and the longer the hair is, the older it is! .

It is imperative that you are given the right by your stylist to approve how much of your split ends are being removed. Even though you may need 1-2 inches removed that's not something you may necessarily want all at once. Make sure you speak up for yourself when you are in the salon chair. A good stylist explains and shows you what needs to be removed to get you on the path to healthy hair.

Mechanical Causes
You
Allowing the ends to freely rub the backs of clothing and to be exposed to the elements is another cause of thinning ends. If your hair is catching and rubbing against the backs of fabrics like cotton and wool that are natural moisture absorbers, this could contribute to your thinner ends. Your cuticle becomes roughed up from the trauma of rubbing and begins to break down. Also exposing your hair to the elements– bitter cold, wind, and sun can also degrade the cuticle and damage the precious ends.
Combing/Styling
You should also get into the habit of controlling your comb as it makes its way down the hair shaft.  You should control your hair with one hand as you attempt to detangle it with your comb in the other hand. Especially near the ends. Gently grasp your hair several inches up from the tips and gently detangle your hair from your hand down. If you get sew-ins every 2-3 months make sure you are removing those dead ends in between installs, because 99.9% they will travel up the hair shaft.Causes more damage than necessary.
Insufficient moisturizing techniquesYour ends require special moisturizing attention. Deep conditioning is a must for protecting against thinning hair ends. Do not skimp on weekly moisturizing conditioning treatments. When you go to apply your daily moisturizer, apply the hair moisturizer to your ends first, then apply to the rest of your hair. The ends are the oldest part and if your hair is at least shoulder length, your ends are about two years old already!

Below is a chart identifying different ways your Hair can split.

Take a quick look at the video.. Its a good example of hair  with thinning split ends.. and also a client Showing and asking if the amount of hair that needs to be trimmed is OK.