Not having a lot of gripping strength in my fingertips (for such things as rethreading pack straps that have slipped out of their buckles), I find pliers an essential tool. I also use them as pot lifters.

Second most useful are scissors, for trimming the hangnails I always seem to get when camping.

My multitool is a Leatherman Squirt PS 4. Tiny but very useful. The blade, although small, will cut most anything (including fingers, so be careful) and is great for frizz sticks if needed (although I rarely build a fire).