Brandilyn Collins talks about this in her excellent writing book, Getting Into Character.
Obviously I’ve never been chased down an abandoned alley in the dead of night with a serial killer on my tail. However, I’ve been scared senseless before.
I bring up that memory—painfully embarrassing though it might be, sigh—which is my jumping off point for writing the intensity of my heroine’s panic.
I close my eyes and picture the scene. For me, it was a dark night and a strange shadow that crossed my window as I lay in bed.
I can feel my terror, hear my wild thoughts, and even my body responds to the memory. I can smell the strangely smokey scent of the recent rain.
(The shadow ended up being my neighbor sitting on the stone wall and smoking, but we won’t go into that.)
I recreate my own terror with my heroine’s terror as she races down that lone alleyway. I copy my thoughts, the feelings in my body, the way fright tastes in my mouth. All those things go into my heroine’s point of view.
(Okay, side note here—I really hope you don’t write a heroine stupid enough to run down a blind alley in the dark with a serial killer on her tail. I mean, come on, people.)
Voila! I’ve just created terror for my character in a situation I’ve never personally been in. I used my own memories to create my heroine’s emotions.
This is a skill every writer should practice and hone, because it enables you to color your emotional writing with more intensity and specificity.