I've mentioned before that I like to have 1/2 inch trimmed off of my hair every 3 to 4 months. While not everyone agrees with trimming while growing their hair, for me, it's a must. Without trims, my ends become very shaggy looking within just a few months. In part that's due to the uneven growth rate of each individual hair. With my fine, pin-straight hair, it's very noticeable.
I like to keep my ends looking as thick as possible while still growing. Yes, cutting off 1/2 inch 3 or 4 times a year inevitably slows my progress to my ultimate goal, but I'm more concerned with the journey than the destination at this point.
I've seen what my hair looks like without a trim for a year, and it isn't at all the way I want my hair to look.
A small trim now and then could mean not having to have a big chop because I suddenly notice that the bottom inches of my hair are transparent, as has happened to me in the past.
If you are someone who likes to have regular trims, it can be difficult to find a hair stylist who really understand that when you say 1/2 inch, you really mean 1/2 inch. Sometimes people don't even realize just how small 1/2 inch is. For me, it's merely the width of the tip of my pinkie finger.
A lot of stylists will not work well with trims that small. Of course there are many who do, but how do you find one? Believe me, it can be hard.
That's why a lot of long-haired people have taken matters into their own hands and self-trim.
I've mentioned before that I'm all thumbs, and I'm honestly not kidding. I can't draw a straight line to save my life and my handwriting is horrendous, even when I'm trying to be neat.
Yet I can trim my own hair! I never thought I'd be able to do it, but I can. It's so easy and just about anyone can do it. On the long hair forums, I discovered Feye's Self-Trim Method. What a revelation! It's a very easy way to trim your hair in tiny amounts. You can also vary between a straight across hemline, a v-shape or a u-shape.
I will suggest that if your hair is only just past your shoulders, it may be helpful to have a friend do the cutting, especially if you're not self-confident, but once your hair is below the under-arm line, you should have no trouble at all doing it yourself.
My second suggestion would be to try cutting off less than you plan to have cut off in total the first or second time you self-trim. You can always cut off a bit more if necessary.
Lastly, make sure you are using very sharp barber shears. These days, you can find good quality barber shears at reasonable prices on Ebay. If you really want to go all out, by all means, go to a professional store to buy your shears. Sharp scissors are essential, not just for a good cut, but also to keep your hair in the best condition. Dull scissors can lead to split ends.
It's a really fine achievement to be independent of having to go to a salon, but to still be able to maintain your own hair. It saves money, and you are also in complete control of your own length.
Here is the link to Feye's Self-Trim Method. If I can do it, believe me, anyone can.
Good luck with it!