Well I wear my hair straight and I learned how to self trim after getting my hair whacked off one too many times over the years from hair dressers that just wanted to "even things up" or "clean up the style" - one stylist even tried to CUT my hair AFTER they wanted it to "lay right".
I have heard it all and dropped each one of them to become a Do It Yourselfer (DIY). Best thing I ever did for my hair!
So...I trim my hair whenever it needs it. I check my ends every time I style the hair.
I dust more often than not and give it a good trim when needed.
1) Section the hair into the way that you style your hair - For me it is Front sides, Top Middle, Back
2) Straighten - Comb small sections through from root to tip and do a mini-trim of the ends. I hold my fingers straight or use a comb as a guide. I have found that it's better to
mini-trim all around the first time and then go back through and finish up. Newbies will sometimes cut off way more than they need to - so mini-trim - love your hair.
3) Repeat the exact same process and literally try only to remove about one eyelash length for each trim. How long is one eyelash?
4) Part the hair down the middle and pull it over both shoulders and make sure it's even on the left and right.
5)THEN - I lean to the right and left and comb the hair down and trim lightly across IF needed. That's it! Whalla! Beautifully trimmed 4a/b (mostly b) hair.
My hair hit bra-strap length and is moving beyond,
so I feel that I must be doing something right! Baby those ends and trim only when needed.
When I went to stylists I STAYED at ear length and shoulder length....now I know why!
If you are trimming layers the process is different. I used to have layers and know how to do that - let me know if anyone wants to know.