Following a reader question, here are a few videos and links on how to self trim without using heat.
Bargain Clipper -This is my exact method. The idea is to braid hair in small sections and just trim off the thinning ends. She actually refers to my blog too .....so thank you I do appreciate it :)
ShidaNatural - There is not much talking in the video but the idea is to do several small twists and clip off whatever you want.
African Export - Video is super informative. She shows how to trim and how to cut layers. She does have a looser curl and knows how to handle her own hair so I would not recommend that you copy the layering technique unless you have a similar curl!
Naptural85 - I think the 90 degree angle thing is not really necessary for natural hair worn curly all the time. However the method is simple and easy (please note the small sections used and twisting up after cutting to keep it separated!)
Rustic Beauty - I would not do the fine comb portion in this video but the rest is excellent. Naturally if your hair is more breakage resistance and you have not had any issues previously with fine tooth combs, then do go right ahead. See the video on youtube.