Steph.
I work mainly in Coloured pencil . Maost recently I started using Flourescent markers as a base to oomph the color intensity and then using coloured pencil over the top. If youve got a nice toothy paper you can wet it numerous times to make the coloured pencil more intense. The problem with using those fluoro markers is the resultant picture cant stand any direct sun. But anyone who would let direct sun fall on a painting under any circumstances is making a mistake.