I use whatever is close by, except when I'm writing in my journal. I always use a pen for that...black ink, no variation in color, that drives me nuts. I don't like different colors mixed together, pen or pencil. When I'm writing a To Do list I use pencil mostly. Brad bought me a set of pencils from Lowe's that I love. I can't remember the name, but they are my favorite. My kid's use them for school work and love them as well.
I'm cheap, and Bic pens work great for me. I like the flow of them, the way they fit in my hand, and the way they flow on the page. I have nice handwriting, and I hate it when a pen is hard to use. I have small hands, so it's something skinny and easy to hold for me. I don't care for gel pens. I have a hard time with them for some reason.