Tip about drawing on watercolor paper.
Use a 4H pencil. It produces a light line and is not likely to smudge if touched with fingers or tools.
“Twirl” the pencil in your finger when making a line of any shape or length. This keeps the line a consistent thickness.
Be very careful when erasing pencil lines on watercolor paper. Erasing with an abrasive eraser will affect the surface of the paper. Watercolor paper comes with a sizing on its surface. Erasunot only removes the pencil line but the sizing as well. A wash over an area that has been erased will show difference. Draw with a light pencil mark and leave them on the paper. The marks will mostly dissolve into the wash never to be seen again.