Saw you had a question on keeping lines straight. Sounds like you got your answer. Im really picky on how my lines turn out. Im nowhere near as talented as some of these guys. but here's what I do. I sharpie my lines that I want, not too concerned about how straight they are. A little wobble here or there is no biggie. If I really dont like the lines a q tip and some rubbing alchol you can fix it.

When I cut my lines I cut the outside of them. All of them. using liquid mask the lines you make arent enough to bleed thru. Once I get all the outside lines cut, I use the rubbing alcohol to remove all sharpie marks. Using something dark, I use black construction paper, as a background. The lines that you have cut should show up pretty clear. Now you can cut the inside lines, with the sharpie marks gone you only can see the line that you have started.

Hope that helps,

Addicted to racing Rc cars