Hi, candycane. My hair is layered too and I'm scared
to have it trimmed by a hairstylist (don't have anyone I can trust right now).
Therefore, I've been doing trims myself since last summer.
I trimmed my hair about a week or two ago. This is what I did:
I washed my hair, conditioned, rinsed. I sectioned my hair in a few sections
and combed out smaller sections (as if I were going to rollerset).
I combed a "small section" out smooth and observed the condition of the ends, sometimes I only cut about 1/2 inch of the hair off. In other sections that looked more wispy and raggedy, I cut up to 1 inch.
I made sure that I cut roughly the same amounts on each SIDE of my head, so I wouldn't end up with a loop-sided style. /images/graemlins/grin.gif
I always made sure to cut the 1 inch pieces off straight across. Even though for the 1/2 inch trims I sometimes just "dusted".
The result? After rollersetting and drying. My ends looked SO MUCH HEALTHIER. No major drama and I can hardly tell I cut 1/2-1 inch.
The difference in length is barely noticeable.
I think if you trim your hair in small sections you should be fine. Just don't cut too much. And use a good sharp pair of hair scissors.