Starting to sketch with the yellow marker to have greater freedom to change my mind while laying the base for the sketch. When I felt I found something interesting I went on to using the black pen to define the correct lines and to create som depth in the sketch as well. This particular sketch is actually an overlay, since I did the original sketch on lined paper and that's why you can't see so much of the yellow "sketch" lines.
Equipment: Yellow copic marker (Y19) and a black medium thick Staedtler pen.
Time: 20 min
I did some sketching the other night and created this car sketch that I kind of liked, but felt it was too messy since I did some late changes of the form of the vehicle which ruined the sketch but in my opinion imporved the design. So I took a marker and filled in the "good" lines and managed to more or less save the sketch.
Equipment: Green ball point pen, a black Copic marker