I just used my mechanical pencil then filled in with my kid's colored pencils. Didn't want to touch those watercolors yet, since I'm sure I would have made a mess. What I find impossible is how to make the "outline" disappear. Also, my drawing looks flat. I need to learn how to shade or whatever you call it to give the subject depth and curves and volume.
My goals in learning to do nature journals are two: to get back to the drawing skills I had when I was younger and/or improve them. 2. To acquire more accurate memories of my walks and hikes or just the times I sit at the window to watch traffic at my bird feeder.