Haha, I made the mistake once of using a pen to do my sketching and then watercoloring. Where was the problem you ask? It was the fact that I didn't use a waterproof
ink pen. It was quite drastic. Lol.
But I do agree with mdog
, I like pen because then I won't correct things. But also, if I'm going to spend a bit more time on something I tend to use a pencil. Haha, I change my mind a lot if you can't tell... Honestly, that's what I would do - change your mind and try all different ways and materials and whatnot.
Haha, I wonder if any of that was worthwhile!